# SOME DESCRIPTIVE TITLE.
#
# Translators:
# nramire1 nramire1, 2017
# Néstor, 2017
msgid ""
msgstr ""
"Project-Id-Version: PostGIS\n"
"Report-Msgid-Bugs-To: https://bugs.kde.org\n"
"POT-Creation-Date: 2021-11-08 06:12+0000\n"
"PO-Revision-Date: 2021-11-28 22:08+0000\n"
"Last-Translator: Regina Obe\n"
"Language-Team: Spanish (http://www.transifex.com/postgis/postgis/language/es/)\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Language: es\n"
"Plural-Forms: nplurals=2; plural=(n != 1);\n"
#. Tag: para
#: reference_processing.xml:5
#, no-c-format
msgid ""
"These functions compute geometric constructions, or alter geometry size or "
"shape."
msgstr ""
#. Tag: title
#: reference_processing.xml:11
#, no-c-format
msgid "Geometry Processing"
msgstr "Procesamiento de geometría"
#. Tag: refname
#: reference_processing.xml:15
#, no-c-format
msgid "ST_Buffer"
msgstr "ST_Buffer"
#. Tag: refpurpose
#: reference_processing.xml:17
#, no-c-format
msgid ""
"Computes a geometry covering all points within a given distance from a "
"geometry."
msgstr ""
#. Tag: funcsynopsis
#: reference_processing.xml:23
#, no-c-format
msgid ""
"<funcprototype> <funcdef>geometry <function>ST_Buffer</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>g1</parameter></paramdef> "
"<paramdef><type>float </type> "
"<parameter>radius_of_buffer</parameter></paramdef> <paramdef "
"choice=\"opt\"><type>text </type> <parameter>buffer_style_parameters = "
"''</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>geometry"
" <function>ST_Buffer</function></funcdef> <paramdef><type>geometry </type> "
"<parameter>g1</parameter></paramdef> <paramdef><type>float </type> "
"<parameter>radius_of_buffer</parameter></paramdef> <paramdef><type>integer "
"</type> <parameter>num_seg_quarter_circle</parameter></paramdef> "
"</funcprototype> <funcprototype> <funcdef>geography "
"<function>ST_Buffer</function></funcdef> <paramdef><type>geography </type> "
"<parameter>g1</parameter></paramdef> <paramdef><type>float </type> "
"<parameter>radius_of_buffer</parameter></paramdef> <paramdef "
"choice=\"opt\"><type>text </type> "
"<parameter>buffer_style_parameters</parameter></paramdef> </funcprototype> "
"<funcprototype> <funcdef>geography <function>ST_Buffer</function></funcdef> "
"<paramdef><type>geography </type> <parameter>g1</parameter></paramdef> "
"<paramdef><type>float </type> "
"<parameter>radius_of_buffer</parameter></paramdef> <paramdef><type>integer "
"</type> <parameter>num_seg_quarter_circle</parameter></paramdef> "
"</funcprototype>"
msgstr ""
#. Tag: title
#: reference_processing.xml:57 reference_processing.xml:308
#: reference_processing.xml:390 reference_processing.xml:511
#: reference_processing.xml:665 reference_processing.xml:739
#: reference_processing.xml:838 reference_processing.xml:897
#: reference_processing.xml:972 reference_processing.xml:1047
#: reference_processing.xml:1094 reference_processing.xml:1155
#: reference_processing.xml:1209 reference_processing.xml:1246
#: reference_processing.xml:1305 reference_processing.xml:1456
#: reference_processing.xml:1507 reference_processing.xml:1565
#: reference_processing.xml:1631 reference_processing.xml:1707
#: reference_processing.xml:1757 reference_processing.xml:1798
#: reference_processing.xml:1839 reference_processing.xml:1886
#: reference_processing.xml:1954 reference_processing.xml:2042
#, no-c-format
msgid "Description"
msgstr "Descripción"
#. Tag: para
#: reference_processing.xml:59
#, no-c-format
msgid ""
"Computes a a POLYGON or MULTIPOLYGON that represents all points whose "
"distance from a geometry/geography is less than or equal to a given "
"distance. A negative distance shrinks the geometry rather than expanding it."
" A negative distance may shrink a polygon completely, in which case POLYGON "
"EMPTY is returned. For points and lines negative distances always return "
"empty results."
msgstr ""
#. Tag: para
#: reference_processing.xml:65
#, no-c-format
msgid ""
"For geometry, the distance is specified in the units of the Spatial "
"Reference System of the geometry. For geography, the distance is specified "
"in meters."
msgstr ""
#. Tag: para
#: reference_processing.xml:69
#, no-c-format
msgid ""
"The optional third parameter controls the buffer accuracy and style. The "
"accuracy of circular arcs in the buffer is specified as the number of line "
"segments used to approximate a quarter circle (default is 8). The buffer "
"style can be specifed by providing a list of blank-separated key=value pairs"
" as follows:"
msgstr ""
#. Tag: para
#: reference_processing.xml:76
#, no-c-format
msgid ""
"'quad_segs=#' : number of line segments used to approximate a quarter circle"
" (default is 8)."
msgstr ""
#. Tag: para
#: reference_processing.xml:79
#, no-c-format
msgid ""
"'endcap=round|flat|square' : endcap style (defaults to \"round\"). 'butt' is"
" accepted as a synonym for 'flat'."
msgstr ""
#. Tag: para
#: reference_processing.xml:82
#, no-c-format
msgid ""
"'join=round|mitre|bevel' : join style (defaults to \"round\"). 'miter' is "
"accepted as a synonym for 'mitre'."
msgstr ""
#. Tag: para
#: reference_processing.xml:85
#, no-c-format
msgid ""
"'mitre_limit=#.#' : mitre ratio limit (only affects mitered join style). "
"'miter_limit' is accepted as a synonym for 'mitre_limit'."
msgstr ""
#. Tag: para
#: reference_processing.xml:88
#, no-c-format
msgid ""
"'side=both|left|right' : 'left' or 'right' performs a single-sided buffer on"
" the geometry, with the buffered side relative to the direction of the line."
" This is only applicable to LINESTRING geometry and does not affect POINT or"
" POLYGON geometries. By default end caps are square."
msgstr ""
#. Tag: para
#: reference_processing.xml:94
#, no-c-format
msgid ""
"For geography, this is a wrapper around the geometry implementation. It "
"determines a planar spatial reference system that best fits the bounding box"
" of the geography object (trying UTM, Lambert Azimuthal Equal Area (LAEA) "
"North/South pole, and finally Mercator ). The buffer is computed in the "
"planar space, and then transformed back to WGS84. This may not produce the "
"desired behavior if the input object is much larger than a UTM zone or "
"crosses the dateline"
msgstr ""
#. Tag: para
#: reference_processing.xml:101
#, no-c-format
msgid ""
"Buffer output is always a valid polygonal geometry. Buffer can handle "
"invalid inputs, so buffering by distance 0 is sometimes used as a way of "
"repairing invalid polygons. <xref linkend=\"ST_MakeValid\"/> can also be "
"used for this purpose."
msgstr ""
#. Tag: para
#: reference_processing.xml:107
#, no-c-format
msgid ""
"Buffering is sometimes used to perform a within-distance search. For this "
"use case it is more efficient to use <xref linkend=\"ST_DWithin\"/>."
msgstr ""
#. Tag: para
#: reference_processing.xml:110 reference_processing.xml:1345
#, no-c-format
msgid ""
"This function ignores the Z dimension. It always gives a 2D result even when"
" used on a 3D geometry."
msgstr ""
#. Tag: para
#: reference_processing.xml:113
#, no-c-format
msgid ""
"Enhanced: 2.5.0 - ST_Buffer geometry support was enhanced to allow for side "
"buffering specification <code>side=both|left|right</code>."
msgstr ""
#. Tag: para
#: reference_processing.xml:114
#, no-c-format
msgid ""
"Availability: 1.5 - ST_Buffer was enhanced to support different endcaps and "
"join types. These are useful for example to convert road linestrings into "
"polygon roads with flat or square edges instead of rounded edges. Thin "
"wrapper for geography was added."
msgstr ""
#. Tag: para
#: reference_processing.xml:118 reference_processing.xml:749
#: reference_processing.xml:1057 reference_processing.xml:1165
#: reference_processing.xml:1341 reference_processing.xml:1525
#: reference_processing.xml:1636 reference_processing.xml:1766
#: reference_processing.xml:1972 reference_processing.xml:2063
#, no-c-format
msgid "Performed by the GEOS module."
msgstr "Realizado por el módulo GEOS."
#. Tag: para
#: reference_processing.xml:119 reference_processing.xml:687
#, no-c-format
msgid "&sfs_compliant; s2.1.1.3"
msgstr "&sfs_compliant; s2.1.1.3"
#. Tag: para
#: reference_processing.xml:120
#, no-c-format
msgid "&sqlmm_compliant; SQL-MM 3: 5.1.17"
msgstr "&sqlmm_compliant; SQL-MM 3: 5.1.17"
#. Tag: title
#: reference_processing.xml:125 reference_processing.xml:326
#: reference_processing.xml:424 reference_processing.xml:555
#: reference_processing.xml:693 reference_processing.xml:856
#: reference_processing.xml:911 reference_processing.xml:1001
#: reference_processing.xml:1063 reference_processing.xml:1111
#: reference_processing.xml:1175 reference_processing.xml:1221
#: reference_processing.xml:1266 reference_processing.xml:1351
#: reference_processing.xml:1473 reference_processing.xml:1596
#: reference_processing.xml:1729 reference_processing.xml:1771
#: reference_processing.xml:1811 reference_processing.xml:1856
#: reference_processing.xml:1913 reference_processing.xml:1978
#: reference_processing.xml:2069
#, no-c-format
msgid "Examples"
msgstr "Ejemplos"
#. Tag: para
#: reference_processing.xml:136
#, no-c-format
msgid "quad_segs=8 (default)"
msgstr "quad_segs=8 (por defecto)"
#. Tag: programlisting
#: reference_processing.xml:139
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText('POINT(100 90)'),\n"
" 50, 'quad_segs=8');"
msgstr "SELECT ST_Buffer(\n ST_GeomFromText('POINT(100 90)'),\n 50, 'quad_segs=8');"
#. Tag: para
#: reference_processing.xml:147
#, no-c-format
msgid "quad_segs=2 (lame)"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:150
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText('POINT(100 90)'),\n"
" 50, 'quad_segs=2');"
msgstr ""
#. Tag: para
#: reference_processing.xml:159
#, no-c-format
msgid "endcap=round join=round (default)"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:162
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'endcap=round join=round');"
msgstr ""
#. Tag: para
#: reference_processing.xml:170
#, no-c-format
msgid "endcap=square"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:173
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'endcap=square join=round');"
msgstr ""
#. Tag: para
#: reference_processing.xml:181
#, no-c-format
msgid "endcap=flat"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:184
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'endcap=flat join=round');"
msgstr ""
#. Tag: para
#: reference_processing.xml:193
#, no-c-format
msgid "join=bevel"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:196
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'join=bevel');"
msgstr ""
#. Tag: para
#: reference_processing.xml:204
#, no-c-format
msgid "join=mitre mitre_limit=5.0 (default mitre limit)"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:207
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'join=mitre mitre_limit=5.0');"
msgstr ""
#. Tag: para
#: reference_processing.xml:215
#, no-c-format
msgid "join=mitre mitre_limit=1"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:218
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'join=mitre mitre_limit=1.0');"
msgstr ""
#. Tag: para
#: reference_processing.xml:227
#, no-c-format
msgid "side=left"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:230
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'side=left');"
msgstr ""
#. Tag: para
#: reference_processing.xml:238
#, no-c-format
msgid "side=right"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:241
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'side=right');"
msgstr ""
#. Tag: para
#: reference_processing.xml:249
#, no-c-format
msgid "side=left join=mitre"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:252
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'\n"
" ), 10, 'side=left join=mitre');"
msgstr ""
#. Tag: para
#: reference_processing.xml:261
#, no-c-format
msgid "right-hand-winding, polygon boundary side=left"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:264
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
"ST_ForceRHR(\n"
"ST_Boundary(\n"
" ST_GeomFromText(\n"
"'POLYGON ((50 50, 50 150, 150 150, 150 50, 50 50))'))),\n"
" ), 20, 'side=left');"
msgstr ""
#. Tag: para
#: reference_processing.xml:271
#, no-c-format
msgid "right-hand-winding, polygon boundary side=right"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:274
#, no-c-format
msgid ""
"SELECT ST_Buffer(\n"
"ST_ForceRHR(\n"
"ST_Boundary(\n"
" ST_GeomFromText(\n"
"'POLYGON ((50 50, 50 150, 150 150, 150 50, 50 50))'))\n"
"), 20,'side=right')"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:281
#, no-c-format
msgid ""
"--A buffered point approximates a circle\n"
"-- A buffered point forcing approximation of (see diagram)\n"
"-- 2 points per quarter circle is poly with 8 sides (see diagram)\n"
"SELECT ST_NPoints(ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50)) As promisingcircle_pcount,\n"
"ST_NPoints(ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50, 2)) As lamecircle_pcount;\n"
"\n"
"promisingcircle_pcount | lamecircle_pcount\n"
"------------------------+-------------------\n"
" 33 | 9\n"
"\n"
"--A lighter but lamer circle\n"
"-- only 2 points per quarter circle is an octagon\n"
"--Below is a 100 meter octagon\n"
"-- Note coordinates are in NAD 83 long lat which we transform\n"
"to Mass state plane meter and then buffer to get measurements in meters;\n"
"SELECT ST_AsText(ST_Buffer(\n"
"ST_Transform(\n"
"ST_SetSRID(ST_Point(-71.063526, 42.35785),4269), 26986)\n"
",100,2)) As octagon;\n"
"----------------------\n"
"POLYGON((236057.59057465 900908.759918696,236028.301252769 900838.049240578,235\n"
"957.59057465 900808.759918696,235886.879896532 900838.049240578,235857.59057465\n"
"900908.759918696,235886.879896532 900979.470596815,235957.59057465 901008.759918\n"
"696,236028.301252769 900979.470596815,236057.59057465 900908.759918696))"
msgstr ""
#. Tag: title
#: reference_processing.xml:285 reference_processing.xml:350
#: reference_processing.xml:487 reference_processing.xml:644
#: reference_processing.xml:713 reference_processing.xml:813
#: reference_processing.xml:861 reference_processing.xml:1022
#: reference_processing.xml:1073 reference_processing.xml:1106
#: reference_processing.xml:1133 reference_processing.xml:1170
#: reference_processing.xml:1188 reference_processing.xml:1216
#: reference_processing.xml:1258 reference_processing.xml:1433
#: reference_processing.xml:1479 reference_processing.xml:1536
#: reference_processing.xml:1608 reference_processing.xml:1679
#: reference_processing.xml:1734 reference_processing.xml:1776
#: reference_processing.xml:1816 reference_processing.xml:1861
#: reference_processing.xml:1920 reference_processing.xml:2003
#: reference_processing.xml:2122
#, no-c-format
msgid "See Also"
msgstr "Ver también"
#. Tag: para
#: reference_processing.xml:287
#, no-c-format
msgid ""
", <xref linkend=\"ST_DWithin\"/>, <xref linkend=\"ST_SetSRID\"/>, <xref "
"linkend=\"ST_Transform\"/>, <xref linkend=\"ST_Union\"/>, <xref "
"linkend=\"ST_MakeValid\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:293
#, no-c-format
msgid "ST_BuildArea"
msgstr "ST_BuildArea"
#. Tag: refpurpose
#: reference_processing.xml:295
#, no-c-format
msgid "Creates a polygonal geometry formed by the linework of a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:300
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_BuildArea</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>geom</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:310
#, no-c-format
msgid ""
"Creates an areal geometry formed by the constituent linework of the input "
"geometry. The input can be LINESTRINGS, MULTILINESTRINGS, POLYGONS, "
"MULTIPOLYGONS, and GeometryCollections. The result is a Polygon or "
"MultiPolygon, depending on input. If the input linework does not form "
"polygons, NULL is returned."
msgstr ""
#. Tag: para
#: reference_processing.xml:316
#, no-c-format
msgid "This function assumes all inner geometries represent holes"
msgstr ""
#. Tag: para
#: reference_processing.xml:319
#, no-c-format
msgid ""
"Input linework must be correctly noded for this function to work properly"
msgstr ""
#. Tag: para
#: reference_processing.xml:322 reference_processing.xml:1058
#, no-c-format
msgid "Availability: 1.1.0"
msgstr "Disponibilidad: 1.1.0"
#. Tag: para
#: reference_processing.xml:336
#, no-c-format
msgid "These will create a donut"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:339
#, no-c-format
msgid ""
"--using polygons\n"
"SELECT ST_BuildArea(ST_Collect(smallc,bigc))\n"
"FROM (SELECT\n"
" ST_Buffer(\n"
" ST_GeomFromText('POINT(100 90)'), 25) As smallc,\n"
" ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50) As bigc) As foo;"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:341
#, no-c-format
msgid ""
"--using linestrings\n"
"SELECT ST_BuildArea(ST_Collect(smallc,bigc))\n"
"FROM (SELECT\n"
" ST_ExteriorRing(ST_Buffer(\n"
" ST_GeomFromText('POINT(100 90)'), 25)) As smallc,\n"
" ST_ExteriorRing(ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50)) As bigc) As foo;"
msgstr ""
#. Tag: para
#: reference_processing.xml:352
#, no-c-format
msgid ""
", <xref linkend=\"ST_MakePolygon\"/>, <xref linkend=\"ST_MakeValid\"/>, "
"<xref linkend=\"ST_BdPolyFromText\"/>, <xref "
"linkend=\"ST_BdMPolyFromText\"/> (wrappers to this function with standard "
"OGC interface)"
msgstr ""
#. Tag: refname
#: reference_processing.xml:364
#, no-c-format
msgid "ST_Centroid"
msgstr "ST_Centroid"
#. Tag: refpurpose
#: reference_processing.xml:366
#, no-c-format
msgid "Returns the geometric center of a geometry."
msgstr ""
#. Tag: funcsynopsis
#: reference_processing.xml:370
#, no-c-format
msgid ""
"<funcprototype> <funcdef>geometry <function>ST_Centroid</function></funcdef>"
" <paramdef><type>geometry </type> <parameter>g1</parameter></paramdef> "
"</funcprototype> <funcprototype> <funcdef>geography "
"<function>ST_Centroid</function></funcdef> <paramdef><type>geography </type>"
" <parameter>g1</parameter></paramdef> <paramdef choice=\"opt\"><type>boolean"
" </type> <parameter>use_spheroid=true</parameter></paramdef> "
"</funcprototype>"
msgstr ""
#. Tag: para
#: reference_processing.xml:392
#, no-c-format
msgid ""
"Computes a point which is the geometric center of mass of a geometry. For "
"[<varname>MULTI</varname>]<varname>POINT</varname>s, the centroid is the "
"arithmetic mean of the input coordinates. For "
"[<varname>MULTI</varname>]<varname>LINESTRING</varname>s, the centroid is "
"computed using the weighted length of each line segment. For "
"[<varname>MULTI</varname>]<varname>POLYGON</varname>s, the centroid is "
"computed in terms of area. If an empty geometry is supplied, an empty "
"<varname>GEOMETRYCOLLECTION</varname> is returned. If "
"<varname>NULL</varname> is supplied, <varname>NULL</varname> is returned. If"
" <varname>CIRCULARSTRING</varname> or <varname>COMPOUNDCURVE</varname> are "
"supplied, they are converted to linestring with CurveToLine first, then same"
" than for <varname>LINESTRING</varname>"
msgstr ""
#. Tag: para
#: reference_processing.xml:405
#, no-c-format
msgid ""
"For mixed-dimension input, the result is equal to the centroid of the "
"component Geometries of highest dimension (since the lower-dimension "
"geometries contribute zero \"weight\" to the centroid)."
msgstr ""
#. Tag: para
#: reference_processing.xml:408
#, no-c-format
msgid ""
"Note that for polygonal geometries the centroid does not necessarily lie in "
"the interior of the polygon. For example, see the diagram below of the "
"centroid of a C-shaped polygon. To construct a point guaranteed to lie in "
"the interior of a polygon use <xref linkend=\"ST_PointOnSurface\"/>."
msgstr ""
#. Tag: para
#: reference_processing.xml:415
#, no-c-format
msgid ""
"New in 2.3.0 : supports <varname>CIRCULARSTRING</varname> and "
"<varname>COMPOUNDCURVE</varname> (using CurveToLine)"
msgstr ""
#. Tag: para
#: reference_processing.xml:417
#, no-c-format
msgid "Availability: 2.4.0 support for geography was introduced."
msgstr ""
#. Tag: para
#: reference_processing.xml:419
#, no-c-format
msgid "&sfs_compliant;"
msgstr "&sfs_compliant;"
#. Tag: para
#: reference_processing.xml:420
#, no-c-format
msgid "&sqlmm_compliant; SQL-MM 3: 8.1.4, 9.5.5"
msgstr ""
#. Tag: para
#: reference_processing.xml:426
#, no-c-format
msgid ""
"In the following illustrations the green dot is the centroid of the source "
"geometry."
msgstr ""
#. Tag: para
#: reference_processing.xml:439
#, no-c-format
msgid "Centroid of a <varname>MULTIPOINT</varname>"
msgstr ""
#. Tag: para
#: reference_processing.xml:450
#, no-c-format
msgid "Centroid of a <varname>LINESTRING</varname>"
msgstr ""
#. Tag: para
#: reference_processing.xml:463
#, no-c-format
msgid "Centroid of a <varname>POLYGON</varname>"
msgstr ""
#. Tag: para
#: reference_processing.xml:474
#, no-c-format
msgid "Centroid of a <varname>GEOMETRYCOLLECTION</varname>"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:483
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_Centroid('MULTIPOINT ( -1 0, -1 2, -1 3, -1 4, -1 7, 0 1, 0 3, 1 1, 2 0, 6 0, 7 8, 9 8, 10 6 )'));\n"
" st_astext\n"
"------------------------------------------\n"
" POINT(2.30769230769231 3.30769230769231)\n"
"(1 row)\n"
"\n"
"SELECT ST_AsText(ST_centroid(g))\n"
"FROM ST_GeomFromText('CIRCULARSTRING(0 2, -1 1,0 0, 0.5 0, 1 0, 2 1, 1 2, 0.5 2, 0 2)') AS g ;\n"
"------------------------------------------\n"
"POINT(0.5 1)\n"
"\n"
"\n"
"SELECT ST_AsText(ST_centroid(g))\n"
"FROM ST_GeomFromText('COMPOUNDCURVE(CIRCULARSTRING(0 2, -1 1,0 0),(0 0, 0.5 0, 1 0),CIRCULARSTRING( 1 0, 2 1, 1 2),(1 2, 0.5 2, 0 2))' ) AS g;\n"
"------------------------------------------\n"
"POINT(0.5 1)"
msgstr ""
#. Tag: para
#: reference_processing.xml:489
#, no-c-format
msgid ", <xref linkend=\"ST_GeometricMedian\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:495
#, no-c-format
msgid "ST_ConcaveHull"
msgstr "ST_ConcaveHull"
#. Tag: refpurpose
#: reference_processing.xml:496
#, no-c-format
msgid ""
"Computes a possibly concave geometry that encloses all input geometry "
"vertices"
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:501
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_ConcaveHull</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>geom</parameter></paramdef> "
"<paramdef><type>float </type> "
"<parameter>target_percent</parameter></paramdef> <paramdef "
"choice=\"opt\"><type>boolean </type> <parameter>allow_holes = "
"false</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:512
#, no-c-format
msgid ""
"A concave hull of a geometry represents a possibly concave geometry that "
"encloses the input geometry. The result is a single polygon, line or point. "
"It will not contain holes unless the optional <varname>allow_holes</varname>"
" argument is specified as true."
msgstr ""
#. Tag: para
#: reference_processing.xml:518
#, no-c-format
msgid ""
"One can think of a concave hull as a geometry obtained by \"shrink-"
"wrapping\" a set of geometries. This is different to the convex hull, which "
"is more like wrapping a rubber band around the geometries. It is slower to "
"compute than the convex hull but generally has a smaller area and represents"
" a more natural boundary for the input geometry."
msgstr ""
#. Tag: para
#: reference_processing.xml:523
#, no-c-format
msgid ""
"The <varname>target_percent</varname> is the percentage of area of the "
"convex hull the solution tries to approach. A target_percent of 1 gives the "
"same result as the convex hull. A target_percent between 0 and 0.99 produces"
" a result that should have a smaller area than the convex hull."
msgstr ""
#. Tag: para
#: reference_processing.xml:528
#, no-c-format
msgid ""
"The smaller the target percent, the longer it takes to process the concave "
"hull, and the more likely to run into topological exceptions. Also the more "
"floating points and number of points you accrue. First try 0.99 which does a"
" single pass, is usually very fast, sometimes as fast as computing the "
"convex hull, and usually gives much better than 99% of shrink since it "
"almost always overshoots. Second hope of 0.98 is slower, others get slower "
"usually quadratically. To reduce precision and float points, use <xref "
"linkend=\"ST_SimplifyPreserveTopology\"/> or <xref "
"linkend=\"ST_SnapToGrid\"/> after ST_ConcaveHull. ST_SnapToGrid is a bit "
"faster, but could result in invalid geometries whereas "
"ST_SimplifyPreserveTopology almost always preserves the validity of the "
"geometry."
msgstr ""
#. Tag: para
#: reference_processing.xml:534
#, no-c-format
msgid ""
"This is not an aggregate function. To compute the concave hull of a set of "
"geometries, use with <xref linkend=\"ST_Collect\"/> or <xref "
"linkend=\"ST_Union\"/> (e.g. "
"<code>ST_ConcaveHull(ST_Collect(somepointfield), 0.80)</code>."
msgstr ""
#. Tag: para
#: reference_processing.xml:539
#, no-c-format
msgid ""
"For use with sets of points or linestrings use <code>ST_Collect</code>. Use "
"<code>ST_Union</code> for polygons, since it may fail with invalid "
"geometries."
msgstr ""
#. Tag: para
#: reference_processing.xml:542
#, no-c-format
msgid ""
"More real world examples and brief explanation of the technique are shown "
"<ulink "
"url=\"http://www.bostongis.com/postgis_concavehull.snippet\">http://www.bostongis.com/postgis_concavehull.snippet</ulink>"
msgstr ""
#. Tag: para
#: reference_processing.xml:545
#, no-c-format
msgid ""
"Also check out Simon Greener's article on demonstrating ConcaveHull "
"introduced in Oracle 11G R2. <ulink "
"url=\"http://www.spatialdbadvisor.com/oracle_spatial_tips_tricks/172"
"/concave-hull-geometries-in-oracle-"
"11gr2\">http://www.spatialdbadvisor.com/oracle_spatial_tips_tricks/172"
"/concave-hull-geometries-in-oracle-11gr2</ulink>. The solution we get at "
"0.75 target percent of convex hull is similar to the shape Simon gets with "
"Oracle SDO_CONCAVEHULL_BOUNDARY."
msgstr ""
#. Tag: para
#: reference_processing.xml:549 reference_processing.xml:685
#, no-c-format
msgid "Performed by the GEOS module"
msgstr "Realizado por el módulo de GEOS"
#. Tag: para
#: reference_processing.xml:551 reference_processing.xml:1637
#, no-c-format
msgid "Availability: 2.0.0"
msgstr "Disponibilidad: 2.0.0"
#. Tag: programlisting
#: reference_processing.xml:556
#, no-c-format
msgid ""
"--Get estimate of infected area based on point observations\n"
"SELECT d.disease_type,\n"
" ST_ConcaveHull(ST_Collect(d.pnt_geom), 0.99) As geom\n"
" FROM disease_obs As d\n"
" GROUP BY d.disease_type;"
msgstr ""
#. Tag: para
#: reference_processing.xml:566
#, no-c-format
msgid ""
"ST_ConcaveHull of 2 polygons encased in target 100% shrink concave hull"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:569
#, no-c-format
msgid ""
"-- geometries overlaid with concavehull\n"
"-- at target 100% shrink (this is the same as convex hull - since no shrink)\n"
"SELECT\n"
" ST_ConcaveHull(\n"
" ST_Union(ST_GeomFromText('POLYGON((175 150, 20 40,\n"
" 50 60, 125 100, 175 150))'),\n"
" ST_Buffer(ST_GeomFromText('POINT(110 170)'), 20)\n"
" ), 1)\n"
" As convexhull;"
msgstr ""
#. Tag: para
#: reference_processing.xml:576
#, no-c-format
msgid ""
"-- geometries overlaid with concavehull at target 90% of convex hull area"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:580
#, no-c-format
msgid ""
"-- geometries overlaid with concavehull at target 90% shrink\n"
"SELECT\n"
" ST_ConcaveHull(\n"
" ST_Union(ST_GeomFromText('POLYGON((175 150, 20 40,\n"
" 50 60, 125 100, 175 150))'),\n"
" ST_Buffer(ST_GeomFromText('POINT(110 170)'), 20)\n"
" ), 0.9)\n"
" As target_90;"
msgstr ""
#. Tag: para
#: reference_processing.xml:589
#, no-c-format
msgid "L Shape points overlaid with convex hull"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:592
#, no-c-format
msgid ""
"-- this produces a table of 42 points that form an L shape\n"
"SELECT (ST_DumpPoints(ST_GeomFromText(\n"
"'MULTIPOINT(14 14,34 14,54 14,74 14,94 14,114 14,134 14,\n"
"150 14,154 14,154 6,134 6,114 6,94 6,74 6,54 6,34 6,\n"
"14 6,10 6,8 6,7 7,6 8,6 10,6 30,6 50,6 70,6 90,6 110,6 130,\n"
"6 150,6 170,6 190,6 194,14 194,14 174,14 154,14 134,14 114,\n"
"14 94,14 74,14 54,14 34,14 14)'))).geom\n"
" INTO TABLE l_shape;\n"
"\n"
"SELECT ST_ConvexHull(ST_Collect(geom))\n"
"FROM l_shape;"
msgstr ""
#. Tag: para
#: reference_processing.xml:599
#, no-c-format
msgid "ST_ConcaveHull of L points at target 99% of convex hull"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:602
#, no-c-format
msgid ""
"SELECT ST_ConcaveHull(ST_Collect(geom), 0.99)\n"
" FROM l_shape;"
msgstr ""
#. Tag: para
#: reference_processing.xml:611
#, no-c-format
msgid "Concave Hull of L points at target 80% convex hull area"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:614
#, no-c-format
msgid ""
"-- Concave Hull L shape points\n"
" -- at target 80% of convexhull\n"
" SELECT ST_ConcaveHull(ST_Collect(geom), 0.80)\n"
" FROM l_shape;"
msgstr ""
#. Tag: para
#: reference_processing.xml:623
#, no-c-format
msgid "multilinestring overlaid with Convex hull"
msgstr ""
#. Tag: para
#: reference_processing.xml:631
#, no-c-format
msgid ""
"multilinestring with overlaid with Concave hull of linestrings at 99% target"
" -- first hop"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:635
#, no-c-format
msgid ""
"SELECT ST_ConcaveHull(ST_GeomFromText('MULTILINESTRING((106 164,30 112,74 70,82 112,130 94,\n"
" 130 62,122 40,156 32,162 76,172 88),\n"
"(132 178,134 148,128 136,96 128,132 108,150 130,\n"
"170 142,174 110,156 96,158 90,158 88),\n"
"(22 64,66 28,94 38,94 68,114 76,112 30,\n"
"132 10,168 18,178 34,186 52,184 74,190 100,\n"
"190 122,182 148,178 170,176 184,156 164,146 178,\n"
"132 186,92 182,56 158,36 150,62 150,76 128,88 118))'),0.99)"
msgstr ""
#. Tag: para
#: reference_processing.xml:645
#, no-c-format
msgid ""
", <xref linkend=\"ST_ConvexHull\"/>, <xref "
"linkend=\"ST_SimplifyPreserveTopology\"/>, <xref linkend=\"ST_SnapToGrid\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:651
#, no-c-format
msgid "ST_ConvexHull"
msgstr "ST_ConvexHull"
#. Tag: refpurpose
#: reference_processing.xml:652
#, no-c-format
msgid "Computes the convex hull of a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:657
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_ConvexHull</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>geomA</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:666
#, no-c-format
msgid ""
"Computes the convex hull of a geometry. The convex hull is the smallest "
"convex geometry that encloses all geometries in the input."
msgstr ""
#. Tag: para
#: reference_processing.xml:670
#, no-c-format
msgid ""
"One can think of the convex hull as the geometry obtained by wrapping an "
"rubber band around a set of geometries. This is different from a concave "
"hull which is analogous to \"shrink-wrapping\" the geometries. A convex hull"
" is often used to determine an affected area based on a set of point "
"observations."
msgstr ""
#. Tag: para
#: reference_processing.xml:676
#, no-c-format
msgid ""
"In the general case the convex hull is a Polygon. The convex hull of two or "
"more collinear points is a two-point LineString. The convex hull of one or "
"more identical points is a Point."
msgstr ""
#. Tag: para
#: reference_processing.xml:680
#, no-c-format
msgid ""
"This is not an aggregate function. To compute the convex hull of a set of "
"geometries, use <xref linkend=\"ST_Collect\"/> to aggregate them into a "
"geometry collection (e.g. <code>ST_ConvexHull(ST_Collect(geom))</code>."
msgstr ""
#. Tag: para
#: reference_processing.xml:688
#, no-c-format
msgid "&sqlmm_compliant; SQL-MM 3: 5.1.16"
msgstr ""
#. Tag: para
#: reference_processing.xml:689 reference_processing.xml:751
#: reference_processing.xml:997 reference_processing.xml:1469
#, no-c-format
msgid "&Z_support;"
msgstr "&Z_support;"
#. Tag: para
#: reference_processing.xml:701
#, no-c-format
msgid "Convex Hull of a MultiLinestring and a MultiPoint"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:704
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_ConvexHull(\n"
" ST_Collect(\n"
" ST_GeomFromText('MULTILINESTRING((100 190,10 8),(150 10, 20 30))'),\n"
" ST_GeomFromText('MULTIPOINT(50 5, 150 30, 50 10, 10 10)')\n"
" )) );\n"
"---st_astext--\n"
"POLYGON((50 5,10 8,10 10,100 190,150 30,150 10,50 5))"
msgstr ""
#. Tag: para
#: reference_processing.xml:707
#, no-c-format
msgid "Using with ST_Collect to compute the convex hulls of geometry sets."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:709
#, no-c-format
msgid ""
"--Get estimate of infected area based on point observations\n"
"SELECT d.disease_type,\n"
" ST_ConvexHull(ST_Collect(d.geom)) As geom\n"
" FROM disease_obs As d\n"
" GROUP BY d.disease_type;"
msgstr ""
#. Tag: para
#: reference_processing.xml:714
#, no-c-format
msgid ""
", <xref linkend=\"ST_ConcaveHull\"/>, <xref "
"linkend=\"ST_MinimumBoundingCircle\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:720
#, no-c-format
msgid "ST_DelaunayTriangles"
msgstr "ST_DelaunayTriangles"
#. Tag: refpurpose
#: reference_processing.xml:722
#, no-c-format
msgid "Returns the Delaunay triangulation of the vertices of a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:729
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_DelaunayTriangles</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>g1</parameter></paramdef> "
"<paramdef><type>float </type> <parameter>tolerance</parameter></paramdef> "
"<paramdef><type>int4 </type> <parameter>flags</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:741
#, no-c-format
msgid ""
"Return the <ulink "
"url=\"http://en.wikipedia.org/wiki/Delaunay_triangulation\">Delaunay "
"triangulation</ulink> of the vertices of the input geometry. Output is a "
"COLLECTION of polygons (for flags=0) or a MULTILINESTRING (for flags=1) or "
"TIN (for flags=2). The tolerance, if any, is used to snap input vertices "
"together."
msgstr ""
#. Tag: para
#: reference_processing.xml:750
#, no-c-format
msgid "Availability: 2.1.0"
msgstr "Disponibilidad: 2.1.0"
#. Tag: para
#: reference_processing.xml:752
#, no-c-format
msgid "&T_support;"
msgstr "&T_support;"
#. Tag: title
#: reference_processing.xml:756
#, no-c-format
msgid "2D Examples"
msgstr "Ejemplos 2D"
#. Tag: para
#: reference_processing.xml:765
#, no-c-format
msgid "Original polygons"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:768
#, no-c-format
msgid ""
"-- our original geometry --\n"
" ST_Union(ST_GeomFromText('POLYGON((175 150, 20 40,\n"
" 50 60, 125 100, 175 150))'),\n"
" ST_Buffer(ST_GeomFromText('POINT(110 170)'), 20)\n"
" )"
msgstr ""
#. Tag: para
#: reference_processing.xml:776
#, no-c-format
msgid ""
"ST_DelaunayTriangles of 2 polygons: delaunay triangle polygons each triangle"
" themed in different color"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:779
#, no-c-format
msgid ""
"-- geometries overlaid multilinestring triangles\n"
"SELECT\n"
" ST_DelaunayTriangles(\n"
" ST_Union(ST_GeomFromText('POLYGON((175 150, 20 40,\n"
" 50 60, 125 100, 175 150))'),\n"
" ST_Buffer(ST_GeomFromText('POINT(110 170)'), 20)\n"
" ))\n"
" As dtriag;"
msgstr ""
#. Tag: para
#: reference_processing.xml:786
#, no-c-format
msgid "-- delaunay triangles as multilinestring"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:789
#, no-c-format
msgid ""
"SELECT\n"
" ST_DelaunayTriangles(\n"
" ST_Union(ST_GeomFromText('POLYGON((175 150, 20 40,\n"
" 50 60, 125 100, 175 150))'),\n"
" ST_Buffer(ST_GeomFromText('POINT(110 170)'), 20)\n"
" ),0.001,1)\n"
" As dtriag;"
msgstr ""
#. Tag: para
#: reference_processing.xml:797
#, no-c-format
msgid "-- delaunay triangles of 45 points as 55 triangle polygons"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:800
#, no-c-format
msgid ""
"-- this produces a table of 42 points that form an L shape\n"
"SELECT (ST_DumpPoints(ST_GeomFromText(\n"
"'MULTIPOINT(14 14,34 14,54 14,74 14,94 14,114 14,134 14,\n"
"150 14,154 14,154 6,134 6,114 6,94 6,74 6,54 6,34 6,\n"
"14 6,10 6,8 6,7 7,6 8,6 10,6 30,6 50,6 70,6 90,6 110,6 130,\n"
"6 150,6 170,6 190,6 194,14 194,14 174,14 154,14 134,14 114,\n"
"14 94,14 74,14 54,14 34,14 14)'))).geom\n"
" INTO TABLE l_shape;\n"
"-- output as individual polygon triangles\n"
"SELECT ST_AsText((ST_Dump(geom)).geom) As wkt\n"
"FROM ( SELECT ST_DelaunayTriangles(ST_Collect(geom)) As geom\n"
"FROM l_shape) As foo;\n"
"\n"
"---wkt ---\n"
"POLYGON((6 194,6 190,14 194,6 194))\n"
"POLYGON((14 194,6 190,14 174,14 194))\n"
"POLYGON((14 194,14 174,154 14,14 194))\n"
"POLYGON((154 14,14 174,14 154,154 14))\n"
"POLYGON((154 14,14 154,150 14,154 14))\n"
"POLYGON((154 14,150 14,154 6,154 14))\n"
":\n"
":"
msgstr ""
#. Tag: title
#: reference_processing.xml:809
#, no-c-format
msgid "3D Examples"
msgstr "Ejemplos 3D"
#. Tag: programlisting
#: reference_processing.xml:810
#, no-c-format
msgid ""
"-- 3D multipoint --\n"
"SELECT ST_AsText(ST_DelaunayTriangles(ST_GeomFromText(\n"
"'MULTIPOINT Z(14 14 10,\n"
"150 14 100,34 6 25, 20 10 150)'))) As wkt;\n"
"\n"
"-----wkt----\n"
"GEOMETRYCOLLECTION Z (POLYGON Z ((14 14 10,20 10 150,34 6 25,14 14 10))\n"
" ,POLYGON Z ((14 14 10,34 6 25,150 14 100,14 14 10)))"
msgstr ""
#. Tag: para
#: reference_processing.xml:814
#, no-c-format
msgid ""
", <xref linkend=\"ST_ConcaveHull\"/>, <xref linkend=\"ST_Dump\"/>, <xref "
"linkend=\"ST_Tesselate\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:821
#, no-c-format
msgid "ST_FilterByM"
msgstr ""
#. Tag: refpurpose
#: reference_processing.xml:822
#, no-c-format
msgid "Removes vertices based on their M value"
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:827
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_FilterByM</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>geom</parameter></paramdef> "
"<paramdef><type>double precision</type> "
"<parameter>min</parameter></paramdef> <paramdef><type>double "
"precision</type> <parameter>max = null</parameter></paramdef> "
"<paramdef><type>boolean</type> <parameter>returnM = "
"false</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:839
#, no-c-format
msgid ""
"Filters out vertex points based on their M-value. Returns a geometry with "
"only vertex points that have a M-value larger or equal to the min value and "
"smaller or equal to the max value. If max-value argument is left out only "
"min value is considered. If fourth argument is left out the m-value will not"
" be in the resulting geometry. If resulting geometry have too few vertex "
"points left for its geometry type an empty geometry will be returned. In a "
"geometry collection geometries without enough points will just be left out "
"silently."
msgstr ""
#. Tag: para
#: reference_processing.xml:845
#, no-c-format
msgid ""
"This function is mainly intended to be used in conjunction with "
"ST_SetEffectiveArea. ST_EffectiveArea sets the effective area of a vertex in"
" its m-value. With ST_FilterByM it then is possible to get a simplified "
"version of the geometry without any calculations, just by filtering"
msgstr ""
#. Tag: para
#: reference_processing.xml:848
#, no-c-format
msgid ""
"There is a difference in what ST_SimplifyVW returns when not enough points "
"meet the criteria compared to ST_FilterByM. ST_SimplifyVW returns the "
"geometry with enough points while ST_FilterByM returns an empty geometry"
msgstr ""
#. Tag: para
#: reference_processing.xml:850
#, no-c-format
msgid "Note that the returned geometry might be invalid"
msgstr ""
#. Tag: para
#: reference_processing.xml:851
#, no-c-format
msgid "This function returns all dimensions, including the Z and M values"
msgstr ""
#. Tag: para
#: reference_processing.xml:852 reference_processing.xml:1252
#: reference_processing.xml:1852
#, no-c-format
msgid "Availability: 2.5.0"
msgstr ""
#. Tag: para
#: reference_processing.xml:857
#, no-c-format
msgid "A linestring is filtered"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:858
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_FilterByM(geom,30)) simplified\n"
"FROM (SELECT ST_SetEffectiveArea('LINESTRING(5 2, 3 8, 6 20, 7 25, 10 10)'::geometry) geom) As foo;\n"
"-result\n"
" simplified\n"
"----------------------------\n"
" LINESTRING(5 2,7 25,10 10)"
msgstr ""
#. Tag: para
#: reference_processing.xml:862 reference_processing.xml:1862
#, no-c-format
msgid ", <xref linkend=\"ST_SimplifyVW\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:868
#, no-c-format
msgid "ST_GeneratePoints"
msgstr "ST_GeneratePoints"
#. Tag: refpurpose
#: reference_processing.xml:870
#, no-c-format
msgid "Generates random points contained in a Polygon or MultiPolygon."
msgstr ""
#. Tag: funcsynopsis
#: reference_processing.xml:874
#, no-c-format
msgid ""
"<funcprototype> <funcdef>geometry "
"<function>ST_GeneratePoints</function></funcdef> <paramdef> "
"<parameter>g</parameter> <type>geometry</type> </paramdef> <paramdef> "
"<parameter>npoints</parameter> <type>integer</type> </paramdef> "
"</funcprototype> <funcprototype> <funcdef>geometry "
"<function>ST_GeneratePoints</function></funcdef> <paramdef> "
"<type>geometry</type> <parameter>g</parameter> </paramdef> <paramdef> "
"<type>integer</type> <parameter>npoints</parameter> </paramdef> <paramdef> "
"<type>integer</type> <parameter>seed</parameter> </paramdef> "
"</funcprototype>"
msgstr ""
#. Tag: para
#: reference_processing.xml:899
#, no-c-format
msgid ""
"ST_GeneratePoints generates a given number of pseudo-random points which lie"
" within the input area. The optional <code>seed</code> is used to regenerate"
" a deterministic sequence of points, and must be greater than zero."
msgstr ""
#. Tag: para
#: reference_processing.xml:906 reference_processing.xml:995
#: reference_processing.xml:1973 reference_processing.xml:2064
#, no-c-format
msgid "Availability: 2.3.0"
msgstr "Disponibilidad: 2.3.0"
#. Tag: para
#: reference_processing.xml:907
#, no-c-format
msgid "Enhanced: 3.0.0, added seed parameter"
msgstr ""
#. Tag: para
#: reference_processing.xml:923
#, no-c-format
msgid "Original Polygon"
msgstr ""
#. Tag: para
#: reference_processing.xml:934
#, no-c-format
msgid ""
"Generated 12 Points overlaid on top of original polygon using a random seed "
"value 1996"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:937
#, no-c-format
msgid ""
"SELECT ST_GeneratePoints(geom, 12, 1996)\n"
"FROM (\n"
" SELECT ST_Buffer(\n"
" ST_GeomFromText(\n"
" 'LINESTRING(50 50,150 150,150 50)'),\n"
" 10, 'endcap=round join=round') AS geom\n"
") AS s;"
msgstr ""
#. Tag: refname
#: reference_processing.xml:948
#, no-c-format
msgid "ST_GeometricMedian"
msgstr "ST_GeometricMedian"
#. Tag: refpurpose
#: reference_processing.xml:952
#, no-c-format
msgid "Returns the geometric median of a MultiPoint."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:959
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_GeometricMedian</function> </funcdef> "
"<paramdef> <type>geometry</type> <parameter>geom</parameter></paramdef> "
"<paramdef choice=\"opt\"><type>float8</type> <parameter>tolerance = "
"NULL</parameter></paramdef> <paramdef choice=\"opt\"><type>int</type> "
"<parameter>max_iter = 10000</parameter></paramdef> <paramdef "
"choice=\"opt\"><type>boolean</type> <parameter>fail_if_not_converged = "
"false</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:974
#, no-c-format
msgid ""
"Computes the approximate geometric median of a MultiPoint geometry using the"
" Weiszfeld algorithm. The geometric median is the point minimizing the sum "
"of distances to the input points. It provides a centrality measure that is "
"less sensitive to outlier points than the centroid (center of mass)."
msgstr ""
#. Tag: para
#: reference_processing.xml:981
#, no-c-format
msgid ""
"The algorithm iterates until the distance change between successive "
"iterations is less than the supplied <varname>tolerance</varname> parameter."
" If this condition has not been met after <varname>max_iterations</varname> "
"iterations, the function produces an error and exits, unless "
"<varname>fail_if_not_converged</varname> is set to <code>false</code> (the "
"default)."
msgstr ""
#. Tag: para
#: reference_processing.xml:988
#, no-c-format
msgid ""
"If a <varname>tolerance</varname> argument is not provided, the tolerance "
"value is calculated based on the extent of the input geometry."
msgstr ""
#. Tag: para
#: reference_processing.xml:992
#, no-c-format
msgid ""
"If present, the input point M values are interpreted as their relative "
"weights."
msgstr ""
#. Tag: para
#: reference_processing.xml:996
#, no-c-format
msgid "Enhanced: 2.5.0 Added support for M as weight of points."
msgstr ""
#. Tag: para
#: reference_processing.xml:998
#, no-c-format
msgid "&M_support;"
msgstr "&M_support;"
#. Tag: para
#: reference_processing.xml:1010
#, no-c-format
msgid ""
"Comparison of the centroid (turquoise point) and geometric median (red "
"point) of a four-point MultiPoint (yellow points)."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1018
#, no-c-format
msgid ""
"WITH test AS (\n"
"SELECT 'MULTIPOINT((0 0), (1 1), (2 2), (200 200))'::geometry geom)\n"
"SELECT\n"
" ST_AsText(ST_Centroid(geom)) centroid,\n"
" ST_AsText(ST_GeometricMedian(geom)) median\n"
"FROM test;\n"
" centroid | median\n"
"--------------------+----------------------------------------\n"
" POINT(50.75 50.75) | POINT(1.9761550281255 1.9761550281255)\n"
"(1 row)"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1031
#, no-c-format
msgid "ST_LineMerge"
msgstr "ST_LineMerge"
#. Tag: refpurpose
#: reference_processing.xml:1033
#, no-c-format
msgid "Return the lines formed by sewing together a MultiLineString."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1039
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_LineMerge</function></funcdef> "
"<paramdef><type>geometry </type> "
"<parameter>amultilinestring</parameter></paramdef>"
msgstr "<funcdef>geometry <function>ST_LineMerge</function></funcdef> <paramdef><type>geometry </type> <parameter>amultilinestring</parameter></paramdef>"
#. Tag: para
#: reference_processing.xml:1049
#, no-c-format
msgid ""
"Returns a LineString or MultiLineString formed by joining together the "
"constituent line work of a MultiLineString. Lines are joined at their "
"endpoints at 2-way intersections. Lines are not joined across intersections "
"of 3-way or greater degree."
msgstr ""
#. Tag: para
#: reference_processing.xml:1055
#, no-c-format
msgid ""
"Only use with MultiLineString/LineStrings. If you pass a Polygon or "
"GeometryCollection into this function, it returns an empty "
"GeometryCollection"
msgstr ""
#. Tag: para
#: reference_processing.xml:1059
#, no-c-format
msgid "This function will strip the M dimension."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1065
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_LineMerge(\n"
"'MULTILINESTRING((-29 -27,-30 -29.7,-36 -31,-45 -33),(-45 -33,-46 -32))'\n"
" ));\n"
"st_astext\n"
"--------------------------------------------------------------------------------------------------\n"
"LINESTRING(-29 -27,-30 -29.7,-36 -31,-45 -33,-46 -32)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1066
#, no-c-format
msgid ""
"If merging is not possible due to non-touching lines, the original "
"MultiLineString is returned."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1068
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_LineMerge(\n"
"'MULTILINESTRING((-29 -27,-30 -29.7,-36 -31,-45 -33),(-45.2 -33.2,-46 -32))'\n"
"));\n"
"st_astext\n"
"----------------\n"
"MULTILINESTRING((-45.2 -33.2,-46 -32),(-29 -27,-30 -29.7,-36 -31,-45 -33))"
msgstr ""
#. Tag: para
#: reference_processing.xml:1069
#, no-c-format
msgid "Example showing Z-dimension handling."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1070
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_LineMerge(\n"
" 'MULTILINESTRING((-29 -27 11,-30 -29.7 10,-36 -31 5,-45 -33 6), (-29 -27 12,-30 -29.7 5), (-45 -33 1,-46 -32 11))'\n"
" ));\n"
"st_astext\n"
"--------------------------------------------------------------------------------------------------\n"
"LINESTRING Z (-30 -29.7 5,-29 -27 11,-30 -29.7 10,-36 -31 5,-45 -33 1,-46 -32 11)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1074
#, no-c-format
msgid ", <xref linkend=\"ST_LineSubstring\"/>"
msgstr ", <xref linkend=\"ST_LineSubstring\"/>"
#. Tag: refname
#: reference_processing.xml:1080
#, no-c-format
msgid "ST_MaximumInscribedCircle"
msgstr ""
#. Tag: refpurpose
#: reference_processing.xml:1081
#, no-c-format
msgid "Computes the largest circle that is fully contained within a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1086
#, no-c-format
msgid ""
"<funcdef>(geometry, geometry, double precision) "
"<function>ST_MaximumInscribedCircle</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>geom</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1095
#, no-c-format
msgid ""
"Finds the largest circle that is fully contained within a geometry. Returns "
"a record with the center point of the circle, a point on the geometry that "
"is nearest to the center, and the radius of the circle."
msgstr ""
#. Tag: para
#: reference_processing.xml:1099
#, no-c-format
msgid ""
"For polygonal inputs, the circle is inscribed within the external ring, "
"using the internal rings as boundaries. For linear and point inputs, the "
"circle is inscribed within the convex hull of the input, using the input as "
"further boundaries."
msgstr ""
#. Tag: para
#: reference_processing.xml:1102 reference_processing.xml:1592
#, no-c-format
msgid "Availability: 3.1.0 - requires GEOS >= 3.9.0."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1112
#, no-c-format
msgid ""
"SELECT radius, ST_AsText(center) AS center, ST_AsText(nearest) AS nearest\n"
" FROM ST_MaximumInscribedCircle('POLYGON ((50 50, 150 50, 150 150, 50 150, 50 50))')\n"
"\n"
" radius | center | nearest\n"
"--------+----------------+---------------\n"
" 50 | POINT(100 100) | POINT(100 50)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1118
#, no-c-format
msgid ""
"Maximum inscribed circle of a triangle polygon. Center, nearest point, and "
"radius are returned."
msgstr ""
#. Tag: para
#: reference_processing.xml:1127
#, no-c-format
msgid ""
"Maximum inscribed circle of a multi-linestring. Center, nearest point, and "
"radius are returned."
msgstr ""
#. Tag: para
#: reference_processing.xml:1134 reference_processing.xml:1171
#: reference_processing.xml:1189
#, no-c-format
msgid ", <xref linkend=\"ST_MinimumBoundingRadius\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1140
#, no-c-format
msgid "ST_MinimumBoundingCircle"
msgstr "ST_MinimumBoundingCircle"
#. Tag: refpurpose
#: reference_processing.xml:1141
#, no-c-format
msgid ""
"<refpurpose>Returns the smallest circle polygon that contains a "
"geometry.</refpurpose>"
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1146
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_MinimumBoundingCircle</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>geomA</parameter></paramdef> "
"<paramdef choice=\"opt\"><type>integer </type> "
"<parameter>num_segs_per_qt_circ=48</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1156
#, no-c-format
msgid ""
"<para>Returns the smallest circle polygon that contains a geometry.</para>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1157
#, no-c-format
msgid ""
"The circle is approximated by a polygon with a default of 48 segments per "
"quarter circle. Because the polygon is an approximation of the minimum "
"bounding circle, some points in the input geometry may not be contained "
"within the polygon. The approximation can be improved by increasing the "
"number of segments, with little performance penalty. For applications where "
"a polygonal approximation is not suitable, ST_MinimumBoundingRadius may be "
"used."
msgstr ""
#. Tag: para
#: reference_processing.xml:1159
#, no-c-format
msgid ""
"It is often used with MULTI and Geometry Collections. Although it is not an "
"aggregate - you can use it in conjunction with ST_Collect to get the minimum"
" bounding circle of a set of geometries. "
"ST_MinimumBoundingCircle(ST_Collect(somepointfield))."
msgstr ""
#. Tag: para
#: reference_processing.xml:1164
#, no-c-format
msgid ""
"The ratio of the area of a polygon divided by the area of its Minimum "
"Bounding Circle is often referred to as the Roeck test."
msgstr ""
#. Tag: para
#: reference_processing.xml:1166
#, no-c-format
msgid "Availability: 1.4.0"
msgstr "Disponibilidad: 1.4.0"
#. Tag: programlisting
#: reference_processing.xml:1176
#, no-c-format
msgid ""
"SELECT d.disease_type,\n"
" ST_MinimumBoundingCircle(ST_Collect(d.geom)) As geom\n"
" FROM disease_obs As d\n"
" GROUP BY d.disease_type;"
msgstr ""
#. Tag: para
#: reference_processing.xml:1182
#, no-c-format
msgid ""
"Minimum bounding circle of a point and linestring. Using 8 segs to "
"approximate a quarter circle"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1185
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_MinimumBoundingCircle(\n"
" ST_Collect(\n"
" ST_GeomFromText('LINESTRING(55 75,125 150)'),\n"
" ST_Point(20, 80)), 8\n"
" )) As wktmbc;\n"
"wktmbc\n"
"-----------\n"
"POLYGON((135.59714732062 115,134.384753327498 102.690357210921,130.79416296937 90.8537670908995,124.963360620072 79.9451031602111,117.116420743937 70.3835792560632,107.554896839789 62.5366393799277,96.6462329091006 56.70583703063,84.8096427890789 53.115246672502,72.5000000000001 51.9028526793802,60.1903572109213 53.1152466725019,48.3537670908996 56.7058370306299,37.4451031602112 62.5366393799276,27.8835792560632 70.383579256063,20.0366393799278 79.9451031602109,14.20583703063 90.8537670908993,10.615246672502 102.690357210921,9.40285267938019 115,10.6152466725019 127.309642789079,14.2058370306299 139.1462329091,20.0366393799275 150.054896839789,27.883579256063 159.616420743937,\n"
"37.4451031602108 167.463360620072,48.3537670908992 173.29416296937,60.190357210921 176.884753327498,\n"
"72.4999999999998 178.09714732062,84.8096427890786 176.884753327498,96.6462329091003 173.29416296937,107.554896839789 167.463360620072,\n"
"117.116420743937 159.616420743937,124.963360620072 150.054896839789,130.79416296937 139.146232909101,134.384753327498 127.309642789079,135.59714732062 115))"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1195
#, no-c-format
msgid "ST_MinimumBoundingRadius"
msgstr "ST_MinimumBoundingRadius"
#. Tag: refpurpose
#: reference_processing.xml:1196
#, no-c-format
msgid ""
"Returns the center point and radius of the smallest circle that contains a "
"geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1201
#, no-c-format
msgid ""
"<funcdef>(geometry, double precision) "
"<function>ST_MinimumBoundingRadius</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>geom</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1210
#, no-c-format
msgid ""
"Returns a record containing the center point and radius of the smallest "
"circle that contains a geometry."
msgstr ""
#. Tag: para
#: reference_processing.xml:1211
#, no-c-format
msgid ""
"Use in conjunction with <xref linkend=\"ST_Collect\"/> to get the minimum "
"bounding circle of a set of geometries."
msgstr ""
#. Tag: para
#: reference_processing.xml:1212
#, no-c-format
msgid "Availability - 2.3.0"
msgstr "Disponibilidad: 2.3.0"
#. Tag: para
#: reference_processing.xml:1217
#, no-c-format
msgid ", <xref linkend=\"ST_MinimumBoundingCircle\"/>"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1222
#, no-c-format
msgid ""
"SELECT ST_AsText(center), radius FROM ST_MinimumBoundingRadius('POLYGON((26426 65078,26531 65242,26075 65136,26096 65427,26426 65078))');\n"
"\n"
" st_astext | radius\n"
"------------------------------------------+------------------\n"
" POINT(26284.8418027133 65267.1145090825) | 247.436045591407"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1229
#, no-c-format
msgid "ST_OrientedEnvelope"
msgstr ""
#. Tag: refpurpose
#: reference_processing.xml:1230
#, no-c-format
msgid "Returns a minimum-area rectangle containing a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1235
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_OrientedEnvelope</function></funcdef> "
"<paramdef> <type>geometry</type> <parameter>geom</parameter> </paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1247
#, no-c-format
msgid ""
"Returns the minimum-area rotated rectangle enclosing a geometry. Note that "
"more than one such rectangle may exist. May return a Point or LineString in "
"the case of degenerate inputs."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1267
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_OrientedEnvelope('MULTIPOINT ((0 0), (-1 -1), (3 2))'));\n"
"\n"
" st_astext\n"
" ------------------------------------------------\n"
" POLYGON((3 2,2.88 2.16,-1.12 -0.84,-1 -1,3 2))"
msgstr ""
#. Tag: para
#: reference_processing.xml:1274
#, no-c-format
msgid "Oriented envelope of a point and linestring."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1277
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_OrientedEnvelope(\n"
" ST_Collect(\n"
" ST_GeomFromText('LINESTRING(55 75,125 150)'),\n"
" ST_Point(20, 80))\n"
" )) As wktenv;\n"
"wktenv\n"
"-----------\n"
"POLYGON((19.9999999999997 79.9999999999999,33.0769230769229 60.3846153846152,138.076923076924 130.384615384616,125.000000000001 150.000000000001,19.9999999999997 79.9999999999999))"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1284
#, no-c-format
msgid "ST_OffsetCurve"
msgstr "ST_OffsetCurve"
#. Tag: refpurpose
#: reference_processing.xml:1286
#, no-c-format
msgid ""
"Returns an offset line at a given distance and side from an input line."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1294
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_OffsetCurve</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>line</parameter></paramdef> "
"<paramdef><type>float </type> "
"<parameter>signed_distance</parameter></paramdef> <paramdef "
"choice=\"opt\"><type>text </type> "
"<parameter>style_parameters=''</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1307
#, no-c-format
msgid ""
"Return an offset line at a given distance and side from an input line. All "
"points of the returned geometries are not further than the given distance "
"from the input geometry. Useful for computing parallel lines about a center "
"line."
msgstr ""
#. Tag: para
#: reference_processing.xml:1314
#, no-c-format
msgid ""
"For positive distance the offset is on the left side of the input line and "
"retains the same direction. For a negative distance it is on the right side "
"and in the opposite direction."
msgstr ""
#. Tag: para
#: reference_processing.xml:1319
#, no-c-format
msgid ""
"Units of distance are measured in units of the spatial reference system."
msgstr ""
#. Tag: para
#: reference_processing.xml:1322
#, no-c-format
msgid ""
"Note that output may be a MULTILINESTRING or EMPTY for some jigsaw-shaped "
"input geometries."
msgstr ""
#. Tag: para
#: reference_processing.xml:1325
#, no-c-format
msgid ""
"The optional third parameter allows specifying a list of blank-separated "
"key=value pairs to tweak operations as follows:"
msgstr ""
#. Tag: para
#: reference_processing.xml:1330
#, no-c-format
msgid ""
"'quad_segs=#' : number of segments used to approximate a quarter circle "
"(defaults to 8)."
msgstr ""
#. Tag: para
#: reference_processing.xml:1333
#, no-c-format
msgid ""
"'join=round|mitre|bevel' : join style (defaults to \"round\"). 'miter' is "
"also accepted as a synonym for 'mitre'."
msgstr ""
#. Tag: para
#: reference_processing.xml:1336
#, no-c-format
msgid ""
"'mitre_limit=#.#' : mitre ratio limit (only affects mitred join style). "
"'miter_limit' is also accepted as a synonym for 'mitre_limit'."
msgstr ""
#. Tag: para
#: reference_processing.xml:1342
#, no-c-format
msgid "Availability: 2.0"
msgstr "Disponibilidad: 2.0"
#. Tag: para
#: reference_processing.xml:1343
#, no-c-format
msgid ""
"Enhanced: 2.5 - added support for GEOMETRYCOLLECTION and MULTILINESTRING"
msgstr ""
#. Tag: para
#: reference_processing.xml:1352
#, no-c-format
msgid "Compute an open buffer around roads"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1353
#, no-c-format
msgid ""
"SELECT ST_Union(\n"
" ST_OffsetCurve(f.geom, f.width/2, 'quad_segs=4 join=round'),\n"
" ST_OffsetCurve(f.geom, -f.width/2, 'quad_segs=4 join=round')\n"
") as track\n"
"FROM someroadstable;"
msgstr ""
#. Tag: para
#: reference_processing.xml:1363
#, no-c-format
msgid "15, 'quad_segs=4 join=round' original line and its offset 15 units."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1367
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_OffsetCurve(ST_GeomFromText(\n"
"'LINESTRING(164 16,144 16,124 16,104 16,84 16,64 16,\n"
" 44 16,24 16,20 16,18 16,17 17,\n"
" 16 18,16 20,16 40,16 60,16 80,16 100,\n"
" 16 120,16 140,16 160,16 180,16 195)'),\n"
" 15, 'quad_segs=4 join=round'));\n"
"--output --\n"
"LINESTRING(164 1,18 1,12.2597485145237 2.1418070123307,\n"
" 7.39339828220179 5.39339828220179,\n"
" 5.39339828220179 7.39339828220179,\n"
" 2.14180701233067 12.2597485145237,1 18,1 195)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1374
#, no-c-format
msgid "-15, 'quad_segs=4 join=round' original line and its offset -15 units"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1378
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_OffsetCurve(geom,\n"
" -15, 'quad_segs=4 join=round')) As notsocurvy\n"
" FROM ST_GeomFromText(\n"
"'LINESTRING(164 16,144 16,124 16,104 16,84 16,64 16,\n"
" 44 16,24 16,20 16,18 16,17 17,\n"
" 16 18,16 20,16 40,16 60,16 80,16 100,\n"
" 16 120,16 140,16 160,16 180,16 195)') As geom;\n"
"-- notsocurvy --\n"
"LINESTRING(31 195,31 31,164 31)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1387
#, no-c-format
msgid ""
"double-offset to get more curvy, note the first reverses direction, so -30 +"
" 15 = -15"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1390
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_OffsetCurve(ST_OffsetCurve(geom,\n"
" -30, 'quad_segs=4 join=round'), -15, 'quad_segs=4 join=round')) As morecurvy\n"
" FROM ST_GeomFromText(\n"
"'LINESTRING(164 16,144 16,124 16,104 16,84 16,64 16,\n"
" 44 16,24 16,20 16,18 16,17 17,\n"
" 16 18,16 20,16 40,16 60,16 80,16 100,\n"
" 16 120,16 140,16 160,16 180,16 195)') As geom;\n"
"-- morecurvy --\n"
"LINESTRING(164 31,46 31,40.2597485145236 32.1418070123307,\n"
"35.3933982822018 35.3933982822018,\n"
"32.1418070123307 40.2597485145237,31 46,31 195)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1397
#, no-c-format
msgid ""
"double-offset to get more curvy,combined with regular offset 15 to get "
"parallel lines. Overlaid with original."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1400
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_Collect(\n"
" ST_OffsetCurve(geom, 15, 'quad_segs=4 join=round'),\n"
" ST_OffsetCurve(ST_OffsetCurve(geom,\n"
" -30, 'quad_segs=4 join=round'), -15, 'quad_segs=4 join=round')\n"
" )\n"
") As parallel_curves\n"
" FROM ST_GeomFromText(\n"
"'LINESTRING(164 16,144 16,124 16,104 16,84 16,64 16,\n"
" 44 16,24 16,20 16,18 16,17 17,\n"
" 16 18,16 20,16 40,16 60,16 80,16 100,\n"
" 16 120,16 140,16 160,16 180,16 195)') As geom;\n"
"-- parallel curves --\n"
"MULTILINESTRING((164 1,18 1,12.2597485145237 2.1418070123307,\n"
"7.39339828220179 5.39339828220179,5.39339828220179 7.39339828220179,\n"
"2.14180701233067 12.2597485145237,1 18,1 195),\n"
"(164 31,46 31,40.2597485145236 32.1418070123307,35.3933982822018 35.3933982822018,\n"
"32.1418070123307 40.2597485145237,31 46,31 195))"
msgstr ""
#. Tag: para
#: reference_processing.xml:1409
#, no-c-format
msgid "15, 'quad_segs=4 join=bevel' shown with original line"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1412
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_OffsetCurve(ST_GeomFromText(\n"
"'LINESTRING(164 16,144 16,124 16,104 16,84 16,64 16,\n"
" 44 16,24 16,20 16,18 16,17 17,\n"
" 16 18,16 20,16 40,16 60,16 80,16 100,\n"
" 16 120,16 140,16 160,16 180,16 195)'),\n"
" 15, 'quad_segs=4 join=bevel'));\n"
"-- output --\n"
"LINESTRING(164 1,18 1,7.39339828220179 5.39339828220179,\n"
" 5.39339828220179 7.39339828220179,1 18,1 195)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1420
#, no-c-format
msgid "15,-15 collected, join=mitre mitre_limit=2.1"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1423
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_Collect(\n"
" ST_OffsetCurve(geom, 15, 'quad_segs=4 join=mitre mitre_limit=2.2'),\n"
" ST_OffsetCurve(geom, -15, 'quad_segs=4 join=mitre mitre_limit=2.2')\n"
" ) )\n"
" FROM ST_GeomFromText(\n"
"'LINESTRING(164 16,144 16,124 16,104 16,84 16,64 16,\n"
" 44 16,24 16,20 16,18 16,17 17,\n"
" 16 18,16 20,16 40,16 60,16 80,16 100,\n"
" 16 120,16 140,16 160,16 180,16 195)') As geom;\n"
"-- output --\n"
"MULTILINESTRING((164 1,11.7867965644036 1,1 11.7867965644036,1 195),\n"
" (31 195,31 31,164 31))"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1440
#, no-c-format
msgid "ST_PointOnSurface"
msgstr "ST_PointOnSurface"
#. Tag: refpurpose
#: reference_processing.xml:1441
#, no-c-format
msgid "Computes a point guaranteed to lie in a polygon, or on a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1446
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_PointOnSurface</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>g1</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1458
#, no-c-format
msgid ""
"Returns a <varname>POINT</varname> which is guaranteed to lie in the "
"interior of a surface (POLYGON, MULTIPOLYGON, and CURVED POLYGON). In "
"PostGIS this function also works on line and point geometries."
msgstr ""
#. Tag: para
#: reference_processing.xml:1463
#, no-c-format
msgid "&sfs_compliant; s3.2.14.2 // s3.2.18.2"
msgstr ""
#. Tag: para
#: reference_processing.xml:1464
#, no-c-format
msgid ""
"&sqlmm_compliant; SQL-MM 3: 8.1.5, 9.5.6. The specifications define "
"ST_PointOnSurface for surface geometries only. PostGIS extends the function "
"to support all common geometry types. Other databases (Oracle, DB2, ArcSDE) "
"seem to support this function only for surfaces. SQL Server 2008 supports "
"all common geometry types."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1475
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_PointOnSurface('POINT(0 5)'::geometry));\n"
" st_astext\n"
"------------\n"
" POINT(0 5)\n"
"\n"
"SELECT ST_AsText(ST_PointOnSurface('LINESTRING(0 5, 0 10)'::geometry));\n"
" st_astext\n"
"------------\n"
" POINT(0 5)\n"
"\n"
"SELECT ST_AsText(ST_PointOnSurface('POLYGON((0 0, 0 5, 5 5, 5 0, 0 0))'::geometry));\n"
" st_astext\n"
"----------------\n"
" POINT(2.5 2.5)\n"
"\n"
"SELECT ST_AsEWKT(ST_PointOnSurface(ST_GeomFromEWKT('LINESTRING(0 5 1, 0 0 1, 0 10 2)')));\n"
" st_asewkt\n"
"----------------\n"
" POINT(0 0 1)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1480
#, no-c-format
msgid ", <xref linkend=\"ST_MaximumInscribedCircle\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1486
#, no-c-format
msgid "ST_Polygonize"
msgstr "ST_Polygonize"
#. Tag: refpurpose
#: reference_processing.xml:1488
#, no-c-format
msgid ""
"Computes a collection of polygons formed from the linework of a set of "
"geometries."
msgstr ""
#. Tag: funcsynopsis
#: reference_processing.xml:1493
#, no-c-format
msgid ""
"<funcprototype> <funcdef>geometry "
"<function>ST_Polygonize</function></funcdef> <paramdef><type>geometry "
"set</type> <parameter>geomfield</parameter></paramdef> </funcprototype> "
"<funcprototype> <funcdef>geometry "
"<function>ST_Polygonize</function></funcdef> "
"<paramdef><type>geometry[]</type> "
"<parameter>geom_array</parameter></paramdef> </funcprototype>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1509
#, no-c-format
msgid ""
"Creates a GeometryCollection containing the polygons formed by the "
"constituent linework of a set of geometries. Input linework must be "
"correctly noded for this function to work properly."
msgstr ""
#. Tag: para
#: reference_processing.xml:1514
#, no-c-format
msgid ""
"To ensure input is fully noded use <xref linkend=\"ST_Node\"/> on the input "
"geometry before polygonizing."
msgstr ""
#. Tag: para
#: reference_processing.xml:1521
#, no-c-format
msgid ""
"GeometryCollections are often difficult to deal with with third party tools."
" Use <xref linkend=\"ST_Dump\"/> to convert the polygonize result into "
"separate polygons."
msgstr ""
#. Tag: para
#: reference_processing.xml:1527
#, no-c-format
msgid "Availability: 1.0.0RC1"
msgstr "Disponibilidad: 1.0.0RC1"
#. Tag: title
#: reference_processing.xml:1531
#, no-c-format
msgid "Examples: Polygonizing single linestrings"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1532
#, no-c-format
msgid ""
"SELECT ST_AsEWKT(ST_Polygonize(geom_4269)) As geomtextrep\n"
"FROM (SELECT geom_4269 FROM ma.suffolk_edges ORDER BY tlid LIMIT 45) As foo;\n"
"\n"
"geomtextrep\n"
"-------------------------------------\n"
" SRID=4269;GEOMETRYCOLLECTION(POLYGON((-71.040878 42.285678,-71.040943 42.2856,-71.04096 42.285752,-71.040878 42.285678)),\n"
" POLYGON((-71.17166 42.353675,-71.172026 42.354044,-71.17239 42.354358,-71.171794 42.354971,-71.170511 42.354855,\n"
" -71.17112 42.354238,-71.17166 42.353675)))\n"
"(1 row)\n"
"\n"
"--Use ST_Dump to dump out the polygonize geoms into individual polygons\n"
"SELECT ST_AsEWKT((ST_Dump(foofoo.polycoll)).geom) As geomtextrep\n"
"FROM (SELECT ST_Polygonize(geom_4269) As polycoll\n"
" FROM (SELECT geom_4269 FROM ma.suffolk_edges\n"
" ORDER BY tlid LIMIT 45) As foo) As foofoo;\n"
"\n"
"geomtextrep\n"
"------------------------\n"
" SRID=4269;POLYGON((-71.040878 42.285678,-71.040943 42.2856,-71.04096 42.285752,\n"
"-71.040878 42.285678))\n"
" SRID=4269;POLYGON((-71.17166 42.353675,-71.172026 42.354044,-71.17239 42.354358\n"
",-71.171794 42.354971,-71.170511 42.354855,-71.17112 42.354238,-71.17166 42.353675))\n"
"(2 rows)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1537
#, no-c-format
msgid ", <xref linkend=\"ST_Dump\"/>"
msgstr ", <xref linkend=\"ST_Dump\"/>"
#. Tag: refname
#: reference_processing.xml:1546
#, no-c-format
msgid "ST_ReducePrecision"
msgstr ""
#. Tag: refpurpose
#: reference_processing.xml:1548
#, no-c-format
msgid "Returns a valid geometry with points rounded to a grid tolerance."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1553
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_ReducePrecision</function></funcdef> "
"<paramdef><type>geometry </type> <parameter>g</parameter></paramdef> "
"<paramdef><type>float8 </type> <parameter>gridsize</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1567
#, no-c-format
msgid ""
"Returns a valid geometry with all points rounded to the provided grid "
"tolerance, and features below the tolerance removed."
msgstr ""
#. Tag: para
#: reference_processing.xml:1569
#, no-c-format
msgid ""
"Unlike <xref linkend=\"ST_SnapToGrid\"/> the returned geometry will be "
"valid, with no ring self-intersections or collapsed components."
msgstr ""
#. Tag: para
#: reference_processing.xml:1571
#, no-c-format
msgid "Precision reduction can be used to:"
msgstr ""
#. Tag: para
#: reference_processing.xml:1574
#, no-c-format
msgid "match coordinate precision to the data accuracy"
msgstr ""
#. Tag: para
#: reference_processing.xml:1577
#, no-c-format
msgid "reduce the number of coordinates needed to represent a geometry"
msgstr ""
#. Tag: para
#: reference_processing.xml:1580
#, no-c-format
msgid ""
"ensure valid geometry output to formats which use lower precision (e.g. text"
" formats such as WKT, GeoJSON or KML when the number of output decimal "
"places is limited)."
msgstr ""
#. Tag: para
#: reference_processing.xml:1585
#, no-c-format
msgid ""
"export valid geometry to systems which use lower or limited precision (e.g. "
"SDE, Oracle tolerance value)"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1598
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_ReducePrecision('POINT(1.412 19.323)', 0.1));\n"
" st_astext\n"
"-----------------\n"
" POINT(1.4 19.3)\n"
"\n"
"SELECT ST_AsText(ST_ReducePrecision('POINT(1.412 19.323)', 1.0));\n"
" st_astext\n"
"-------------\n"
" POINT(1 19)\n"
"\n"
"SELECT ST_AsText(ST_ReducePrecision('POINT(1.412 19.323)', 10));\n"
" st_astext\n"
"-------------\n"
" POINT(0 20)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1600
#, no-c-format
msgid "Precision reduction can reduce number of vertices"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1601
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_ReducePrecision('LINESTRING (10 10, 19.6 30.1, 20 30, 20.3 30, 40 40)', 1));\n"
" st_astext\n"
"-------------\n"
" LINESTRING (10 10, 20 30, 40 40)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1603
#, no-c-format
msgid "Precision reduction splits polygons if needed to ensure validity"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1604
#, no-c-format
msgid ""
"SELECT ST_AsText(ST_ReducePrecision('POLYGON ((10 10, 60 60.1, 70 30, 40 40, 50 10, 10 10))', 10));\n"
" st_astext\n"
"-------------\n"
" MULTIPOLYGON (((60 60, 70 30, 40 40, 60 60)), ((40 40, 50 10, 10 10, 40 40)))"
msgstr ""
#. Tag: para
#: reference_processing.xml:1610
#, no-c-format
msgid ", <xref linkend=\"ST_Simplify\"/>, <xref linkend=\"ST_SimplifyVW\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1616
#, no-c-format
msgid "ST_SharedPaths"
msgstr "ST_SharedPaths"
#. Tag: refpurpose
#: reference_processing.xml:1617
#, no-c-format
msgid ""
"Returns a collection containing paths shared by the two input "
"linestrings/multilinestrings."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1622
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_SharedPaths</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>lineal1</parameter></paramdef> "
"<paramdef><type>geometry</type> <parameter>lineal2</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1632
#, no-c-format
msgid ""
"Returns a collection containing paths shared by the two input geometries. "
"Those going in the same direction are in the first element of the "
"collection, those going in the opposite direction are in the second element."
" The paths themselves are given in the direction of the first geometry."
msgstr ""
#. Tag: title
#: reference_processing.xml:1640
#, no-c-format
msgid "Examples: Finding shared paths"
msgstr ""
#. Tag: para
#: reference_processing.xml:1650
#, no-c-format
msgid "A multilinestring and a linestring"
msgstr ""
#. Tag: para
#: reference_processing.xml:1661
#, no-c-format
msgid ""
"The shared path of multilinestring and linestring overlaid with original "
"geometries."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1664
#, no-c-format
msgid ""
"SELECT ST_AsText(\n"
" ST_SharedPaths(\n"
" ST_GeomFromText('MULTILINESTRING((26 125,26 200,126 200,126 125,26 125),\n"
" (51 150,101 150,76 175,51 150))'),\n"
" ST_GeomFromText('LINESTRING(151 100,126 156.25,126 125,90 161, 76 175)')\n"
" )\n"
" ) As wkt\n"
"\n"
" wkt\n"
"-------------------------------------------------------------\n"
"GEOMETRYCOLLECTION(MULTILINESTRING((126 156.25,126 125),\n"
" (101 150,90 161),(90 161,76 175)),MULTILINESTRING EMPTY)"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1670
#, no-c-format
msgid ""
"-- same example but linestring orientation flipped\n"
"SELECT ST_AsText(\n"
" ST_SharedPaths(\n"
" ST_GeomFromText('LINESTRING(76 175,90 161,126 125,126 156.25,151 100)'),\n"
" ST_GeomFromText('MULTILINESTRING((26 125,26 200,126 200,126 125,26 125),\n"
" (51 150,101 150,76 175,51 150))')\n"
" )\n"
" ) As wkt\n"
"\n"
" wkt\n"
"-------------------------------------------------------------\n"
"GEOMETRYCOLLECTION(MULTILINESTRING EMPTY,\n"
"MULTILINESTRING((76 175,90 161),(90 161,101 150),(126 125,126 156.25)))"
msgstr ""
#. Tag: para
#: reference_processing.xml:1680
#, no-c-format
msgid ", <xref linkend=\"ST_GeometryN\"/>, <xref linkend=\"ST_NumGeometries\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1690
#, no-c-format
msgid "ST_Simplify"
msgstr "ST_Simplify"
#. Tag: refpurpose
#: reference_processing.xml:1691
#, no-c-format
msgid ""
"Returns a simplified version of a geometry, using the Douglas-Peucker "
"algorithm."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1697
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_Simplify</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>geomA</parameter></paramdef> "
"<paramdef><type>float</type> <parameter>tolerance</parameter></paramdef> "
"<paramdef><type>boolean</type> "
"<parameter>preserveCollapsed</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1708
#, no-c-format
msgid ""
"Returns a \"simplified\" version of the given geometry using the Douglas-"
"Peucker algorithm. Will actually do something only with (multi)lines and "
"(multi)polygons but you can safely call it with any kind of geometry. Since "
"simplification occurs on a object-by-object basis you can also feed a "
"GeometryCollection to this function."
msgstr ""
#. Tag: para
#: reference_processing.xml:1715
#, no-c-format
msgid ""
"The \"preserve collapsed\" flag will retain objects that would otherwise be "
"too small given the tolerance. For example, a 1m long line simplified with a"
" 10m tolerance. If the preserve flag is given, the line will not disappear. "
"This flag is useful for rendering engines, to avoid having large numbers of "
"very small objects disappear from a map leaving surprising gaps."
msgstr ""
#. Tag: para
#: reference_processing.xml:1721 reference_processing.xml:1803
#: reference_processing.xml:1904
#, no-c-format
msgid ""
"Note that returned geometry might lose its simplicity (see <xref "
"linkend=\"ST_IsSimple\"/>)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1723 reference_processing.xml:1805
#: reference_processing.xml:1906
#, no-c-format
msgid ""
"Note topology may not be preserved and may result in invalid geometries. Use"
" (see <xref linkend=\"ST_SimplifyPreserveTopology\"/>) to preserve topology."
msgstr ""
#. Tag: para
#: reference_processing.xml:1725
#, no-c-format
msgid "Availability: 1.2.2"
msgstr "Disponibilidad: 1.2.2"
#. Tag: para
#: reference_processing.xml:1730
#, no-c-format
msgid "A circle simplified too much becomes a triangle, medium an octagon,"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1731
#, no-c-format
msgid ""
"SELECT ST_Npoints(geom) AS np_before,\n"
" ST_NPoints(ST_Simplify(geom,0.1)) AS np01_notbadcircle,\n"
" ST_NPoints(ST_Simplify(geom,0.5)) AS np05_notquitecircle,\n"
" ST_NPoints(ST_Simplify(geom,1)) AS np1_octagon,\n"
" ST_NPoints(ST_Simplify(geom,10)) AS np10_triangle,\n"
" (ST_Simplify(geom,100) is null) AS np100_geometrygoesaway\n"
" FROM\n"
" (SELECT ST_Buffer('POINT(1 3)', 10,12) As geom) AS foo;\n"
"\n"
" np_before | np01_notbadcircle | np05_notquitecircle | np1_octagon | np10_triangle | np100_geometrygoesaway\n"
"-----------+-------------------+---------------------+-------------+---------------+------------------------\n"
" 49 | 33 | 17 | 9 | 4 | t"
msgstr ""
#. Tag: para
#: reference_processing.xml:1735
#, no-c-format
msgid ""
", <xref linkend=\"ST_SimplifyPreserveTopology\"/>, Topology <xref "
"linkend=\"TP_ST_Simplify\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1741
#, no-c-format
msgid "ST_SimplifyPreserveTopology"
msgstr "ST_SimplifyPreserveTopology"
#. Tag: refpurpose
#: reference_processing.xml:1742
#, no-c-format
msgid ""
"Returns a simplified and valid version of a geometry, using the Douglas-"
"Peucker algorithm."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1748
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_SimplifyPreserveTopology</function></funcdef>"
" <paramdef><type>geometry</type> <parameter>geomA</parameter></paramdef> "
"<paramdef><type>float</type> <parameter>tolerance</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1758
#, no-c-format
msgid ""
"Returns a \"simplified\" version of the given geometry using the Douglas-"
"Peucker algorithm. Will avoid creating derived geometries (polygons in "
"particular) that are invalid. Will actually do something only with "
"(multi)lines and (multi)polygons but you can safely call it with any kind of"
" geometry. Since simplification occurs on a object-by-object basis you can "
"also feed a GeometryCollection to this function."
msgstr ""
#. Tag: para
#: reference_processing.xml:1767
#, no-c-format
msgid "Availability: 1.3.3"
msgstr "Disponibilidad: 1.3.3"
#. Tag: para
#: reference_processing.xml:1772
#, no-c-format
msgid ""
"Same example as Simplify, but we see Preserve Topology prevents "
"oversimplification. The circle can at most become a square."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1773
#, no-c-format
msgid ""
"SELECT ST_Npoints(geom) As np_before, ST_NPoints(ST_SimplifyPreserveTopology(geom,0.1)) As np01_notbadcircle, ST_NPoints(ST_SimplifyPreserveTopology(geom,0.5)) As np05_notquitecircle,\n"
"ST_NPoints(ST_SimplifyPreserveTopology(geom,1)) As np1_octagon, ST_NPoints(ST_SimplifyPreserveTopology(geom,10)) As np10_square,\n"
"ST_NPoints(ST_SimplifyPreserveTopology(geom,100)) As np100_stillsquare\n"
"FROM (SELECT ST_Buffer('POINT(1 3)', 10,12) As geom) As foo;\n"
"\n"
"--result--\n"
" np_before | np01_notbadcircle | np05_notquitecircle | np1_octagon | np10_square | np100_stillsquare\n"
"-----------+-------------------+---------------------+-------------+---------------+-------------------\n"
" 49 | 33 | 17 | 9 | 5 | 5"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1783
#, no-c-format
msgid "ST_SimplifyVW"
msgstr "ST_SimplifyVW"
#. Tag: refpurpose
#: reference_processing.xml:1784
#, no-c-format
msgid ""
"Returns a simplified version of a geometry, using the Visvalingam-Whyatt "
"algorithm"
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1789
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_SimplifyVW</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>geomA</parameter></paramdef> "
"<paramdef><type>float</type> <parameter>tolerance</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1799
#, no-c-format
msgid ""
"Returns a \"simplified\" version of the given geometry using the "
"Visvalingam-Whyatt algorithm. Will actually do something only with "
"(multi)lines and (multi)polygons but you can safely call it with any kind of"
" geometry. Since simplification occurs on a object-by-object basis you can "
"also feed a GeometryCollection to this function."
msgstr ""
#. Tag: para
#: reference_processing.xml:1806 reference_processing.xml:1848
#, no-c-format
msgid ""
"This function handles 3D and the third dimension will affect the result."
msgstr ""
#. Tag: para
#: reference_processing.xml:1807 reference_processing.xml:1909
#, no-c-format
msgid "Availability: 2.2.0"
msgstr "Disponibilidad: 2.2.0"
#. Tag: para
#: reference_processing.xml:1812
#, no-c-format
msgid "A LineString is simplified with a minimum area threshold of 30."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1813
#, no-c-format
msgid ""
"select ST_AsText(ST_SimplifyVW(geom,30)) simplified\n"
"FROM (SELECT 'LINESTRING(5 2, 3 8, 6 20, 7 25, 10 10)'::geometry geom) As foo;\n"
"-result\n"
" simplified\n"
"------------------------------\n"
"LINESTRING(5 2,7 25,10 10)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1817
#, no-c-format
msgid ""
", <xref linkend=\"ST_Simplify\"/>, <xref "
"linkend=\"ST_SimplifyPreserveTopology\"/>, Topology <xref "
"linkend=\"TP_ST_Simplify\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1823
#, no-c-format
msgid "ST_ChaikinSmoothing"
msgstr ""
#. Tag: refpurpose
#: reference_processing.xml:1824
#, no-c-format
msgid "Returns a smoothed version of a geometry, using the Chaikin algorithm"
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1829
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_ChaikinSmoothing</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>geom</parameter></paramdef> "
"<paramdef><type>integer</type> <parameter>nIterations = "
"1</parameter></paramdef> <paramdef><type>boolean</type> "
"<parameter>preserveEndPoints = false</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1840
#, no-c-format
msgid ""
"Returns a \"smoothed\" version of the given geometry using the Chaikin "
"algorithm. See <ulink url=\"http://www.idav.ucdavis.edu/education/CAGDNotes"
"/Chaikins-Algorithm/Chaikins-Algorithm.html\">Chaikins-Algorithm</ulink> for"
" an explanation of the process. For each iteration the number of vertex "
"points will double. The function puts new vertex points at 1/4 of the line "
"before and after each point and removes the original point. To reduce the "
"number of points use one of the simplification functions on the result. The "
"new points gets interpolated values for all included dimensions, also z and "
"m."
msgstr ""
#. Tag: para
#: reference_processing.xml:1846
#, no-c-format
msgid "Second argument, number of iterations is limited to max 5 iterations"
msgstr ""
#. Tag: para
#: reference_processing.xml:1847
#, no-c-format
msgid ""
"Note third argument is only valid for polygons, and will be ignored for "
"linestrings"
msgstr ""
#. Tag: para
#: reference_processing.xml:1849
#, no-c-format
msgid ""
"Note that returned geometry will get more points than the original. To "
"reduce the number of points again use one of the simplification functions on"
" the result. (see <xref linkend=\"ST_Simplify\"/> and <xref "
"linkend=\"ST_SimplifyVW\"/>)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1857
#, no-c-format
msgid "A triangle is smoothed"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1858
#, no-c-format
msgid ""
"select ST_AsText(ST_ChaikinSmoothing(geom)) smoothed\n"
"FROM (SELECT 'POLYGON((0 0, 8 8, 0 16, 0 0))'::geometry geom) As foo;\n"
"┌───────────────────────────────────────────┐\n"
"│ smoothed │\n"
"├───────────────────────────────────────────┤\n"
"│ POLYGON((2 2,6 6,6 10,2 14,0 12,0 4,2 2)) │\n"
"└───────────────────────────────────────────┘"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1868
#, no-c-format
msgid "ST_SetEffectiveArea"
msgstr "ST_SetEffectiveArea"
#. Tag: refpurpose
#: reference_processing.xml:1869
#, no-c-format
msgid ""
"Sets the effective area for each vertex, using the Visvalingam-Whyatt "
"algorithm."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1876
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_SetEffectiveArea</function></funcdef> "
"<paramdef><type>geometry</type> <parameter>geomA</parameter></paramdef> "
"<paramdef><type>float</type> <parameter>threshold = 0</parameter></paramdef>"
" <paramdef><type>integer</type> <parameter>set_area = "
"1</parameter></paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1887
#, no-c-format
msgid ""
"Sets the effective area for each vertex, using the Visvalingam-Whyatt "
"algorithm. The effective area is stored as the M-value of the vertex. If the"
" optional \"theshold\" parameter is used, a simplified geometry will be "
"returned, containing only vertices with an effective area greater than or "
"equal to the threshold value."
msgstr ""
#. Tag: para
#: reference_processing.xml:1892
#, no-c-format
msgid ""
"This function can be used for server-side simplification when a threshold is"
" specified. Another option is to use a threshold value of zero. In this "
"case, the full geometry will be returned with effective areas as M-values, "
"which can be used by the client to simplify very quickly."
msgstr ""
#. Tag: para
#: reference_processing.xml:1895
#, no-c-format
msgid ""
"Will actually do something only with (multi)lines and (multi)polygons but "
"you can safely call it with any kind of geometry. Since simplification "
"occurs on a object-by-object basis you can also feed a GeometryCollection to"
" this function."
msgstr ""
#. Tag: para
#: reference_processing.xml:1907
#, no-c-format
msgid "The output geometry will lose all previous information in the M-values"
msgstr ""
#. Tag: para
#: reference_processing.xml:1908
#, no-c-format
msgid ""
"This function handles 3D and the third dimension will affect the effective "
"area"
msgstr ""
#. Tag: para
#: reference_processing.xml:1914
#, no-c-format
msgid ""
"Calculating the effective area of a LineString. Because we use a threshold "
"value of zero, all vertices in the input geometry are returned."
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1917
#, no-c-format
msgid ""
"select ST_AsText(ST_SetEffectiveArea(geom)) all_pts, ST_AsText(ST_SetEffectiveArea(geom,30) ) thrshld_30\n"
"FROM (SELECT 'LINESTRING(5 2, 3 8, 6 20, 7 25, 10 10)'::geometry geom) As foo;\n"
"-result\n"
" all_pts | thrshld_30\n"
"-----------+-------------------+\n"
"LINESTRING M (5 2 3.40282346638529e+38,3 8 29,6 20 1.5,7 25 49.5,10 10 3.40282346638529e+38) | LINESTRING M (5 2 3.40282346638529e+38,7 25 49.5,10 10 3.40282346638529e+38)"
msgstr ""
#. Tag: refname
#: reference_processing.xml:1927
#, no-c-format
msgid "ST_VoronoiLines"
msgstr "ST_VoronoiLines"
#. Tag: refpurpose
#: reference_processing.xml:1929
#, no-c-format
msgid ""
"Returns the boundaries of the Voronoi diagram of the vertices of a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:1934
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_VoronoiLines</function></funcdef> <paramdef> "
"<parameter>g1</parameter> <type>geometry</type> </paramdef> <paramdef "
"choice=\"opt\"> <parameter>tolerance</parameter> <type>float8</type> "
"</paramdef> <paramdef choice=\"opt\"> <parameter>extend_to</parameter> "
"<type>geometry</type> </paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:1955
#, no-c-format
msgid ""
"ST_VoronoiLines computes a two-dimensional <ulink "
"url=\"https://en.wikipedia.org/wiki/Voronoi_diagram\">Voronoi "
"diagram</ulink> from the vertices of the supplied geometry and returns the "
"boundaries between cells in that diagram as a MultiLineString. Returns null "
"if input geometry is null. Returns an empty geometry collection if the input"
" geometry contains only one vertex. Returns an empty geometry collection if "
"the extend_to envelope has zero area."
msgstr ""
#. Tag: para
#: reference_processing.xml:1960 reference_processing.xml:2050
#, no-c-format
msgid "Optional parameters:"
msgstr ""
#. Tag: para
#: reference_processing.xml:1964 reference_processing.xml:2054
#, no-c-format
msgid ""
"'tolerance' : The distance within which vertices will be considered "
"equivalent. Robustness of the algorithm can be improved by supplying a "
"nonzero tolerance distance. (default = 0.0)"
msgstr ""
#. Tag: para
#: reference_processing.xml:1967 reference_processing.xml:2057
#, no-c-format
msgid ""
"'extend_to' : If a geometry is supplied as the \"extend_to\" parameter, the "
"diagram will be extended to cover the envelope of the \"extend_to\" "
"geometry, unless that envelope is smaller than the default envelope (default"
" = NULL, default envelope is boundingbox of input geometry extended by about"
" 50% in each direction)."
msgstr ""
#. Tag: para
#: reference_processing.xml:1988
#, no-c-format
msgid "Voronoi lines with tolerance of 30 units"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:1991 reference_processing.xml:2110
#, no-c-format
msgid ""
"SELECT ST_VoronoiLines(geom, 30) As geom\n"
"FROM (SELECT 'MULTIPOINT (50 30, 60 30, 100 100,10 150, 110 120)'::geometry As geom ) As g"
msgstr ""
#. Tag: screen
#: reference_processing.xml:1992 reference_processing.xml:2111
#, no-c-format
msgid ""
"-- ST_AsText output\n"
"MULTILINESTRING((135.555555555556 270,36.8181818181818 92.2727272727273),(36.8181818181818 92.2727272727273,-110 43.3333333333333),(230 -45.7142857142858,36.8181818181818 92.2727272727273))"
msgstr ""
#. Tag: para
#: reference_processing.xml:2005
#, no-c-format
msgid ", <xref linkend=\"ST_VoronoiPolygons\"/>, <xref linkend=\"ST_Collect\"/>"
msgstr ""
#. Tag: refname
#: reference_processing.xml:2015
#, no-c-format
msgid "ST_VoronoiPolygons"
msgstr "ST_VoronoiPolygons"
#. Tag: refpurpose
#: reference_processing.xml:2017
#, no-c-format
msgid ""
"Returns the cells of the Voronoi diagram of the vertices of a geometry."
msgstr ""
#. Tag: funcprototype
#: reference_processing.xml:2022
#, no-c-format
msgid ""
"<funcdef>geometry <function>ST_VoronoiPolygons</function></funcdef> "
"<paramdef> <parameter>g1</parameter> <type>geometry</type> </paramdef> "
"<paramdef choice=\"opt\"> <parameter>tolerance</parameter> "
"<type>float8</type> </paramdef> <paramdef choice=\"opt\"> "
"<parameter>extend_to</parameter> <type>geometry</type> </paramdef>"
msgstr ""
#. Tag: para
#: reference_processing.xml:2044
#, no-c-format
msgid ""
"ST_VoronoiPolygons computes a two-dimensional <ulink "
"url=\"https://en.wikipedia.org/wiki/Voronoi_diagram\">Voronoi "
"diagram</ulink> from the vertices of the supplied geometry. The result is a "
"GeometryCollection of Polygons that covers an envelope larger than the "
"extent of the input vertices. Returns null if input geometry is null. "
"Returns an empty geometry collection if the input geometry contains only one"
" vertex. Returns an empty geometry collection if the extend_to envelope has "
"zero area."
msgstr ""
#. Tag: para
#: reference_processing.xml:2080
#, no-c-format
msgid "Points overlaid on top of Voronoi diagram"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:2083
#, no-c-format
msgid ""
"SELECT\n"
" ST_VoronoiPolygons(geom) As geom\n"
"FROM (SELECT 'MULTIPOINT (50 30, 60 30, 100 100,10 150, 110 120)'::geometry As geom ) As g;"
msgstr ""
#. Tag: screen
#: reference_processing.xml:2084
#, no-c-format
msgid ""
"-- ST_AsText output\n"
"GEOMETRYCOLLECTION(POLYGON((-110 43.3333333333333,-110 270,100.5 270,59.3478260869565 132.826086956522,36.8181818181818 92.2727272727273,-110 43.3333333333333)),\n"
"POLYGON((55 -90,-110 -90,-110 43.3333333333333,36.8181818181818 92.2727272727273,55 79.2857142857143,55 -90)),\n"
"POLYGON((230 47.5,230 -20.7142857142857,55 79.2857142857143,36.8181818181818 92.2727272727273,59.3478260869565 132.826086956522,230 47.5)),POLYGON((230 -20.7142857142857,230 -90,55 -90,55 79.2857142857143,230 -20.7142857142857)),\n"
"POLYGON((100.5 270,230 270,230 47.5,59.3478260869565 132.826086956522,100.5 270)))"
msgstr ""
#. Tag: para
#: reference_processing.xml:2094
#, no-c-format
msgid "Voronoi with tolerance of 30 units"
msgstr ""
#. Tag: programlisting
#: reference_processing.xml:2097
#, no-c-format
msgid ""
"SELECT ST_VoronoiPolygons(geom, 30) As geom\n"
"FROM (SELECT 'MULTIPOINT (50 30, 60 30, 100 100,10 150, 110 120)'::geometry As geom ) As g;"
msgstr ""
#. Tag: screen
#: reference_processing.xml:2098
#, no-c-format
msgid ""
"-- ST_AsText output\n"
"GEOMETRYCOLLECTION(POLYGON((-110 43.3333333333333,-110 270,100.5 270,59.3478260869565 132.826086956522,36.8181818181818 92.2727272727273,-110 43.3333333333333)),\n"
"POLYGON((230 47.5,230 -45.7142857142858,36.8181818181818 92.2727272727273,59.3478260869565 132.826086956522,230 47.5)),POLYGON((230 -45.7142857142858,230 -90,-110 -90,-110 43.3333333333333,36.8181818181818 92.2727272727273,230 -45.7142857142858)),\n"
"POLYGON((100.5 270,230 270,230 47.5,59.3478260869565 132.826086956522,100.5 270)))"
msgstr ""
#. Tag: para
#: reference_processing.xml:2107
#, no-c-format
msgid "Voronoi with tolerance of 30 units as MultiLineString"
msgstr ""
#. Tag: para
#: reference_processing.xml:2124
#, no-c-format
msgid ", <xref linkend=\"ST_VoronoiLines\"/>, <xref linkend=\"ST_Collect\"/>"
msgstr ""