TTianyu Chenfeat: update numba to 0.59.1+dfsg-2

538c692a创建于 2024年8月6日历史提交

.. _numpy-support:

======================== Supported NumPy features

One objective of Numba is having a seamless integration with NumPy_. NumPy arrays provide an efficient storage method for homogeneous sets of data. NumPy dtypes provide type information useful when compiling, and the regular, structured storage of potentially large amounts of data in memory provides an ideal memory layout for code generation. Numba excels at generating code that executes on top of NumPy arrays.

NumPy support in Numba comes in many forms:

Numba understands calls to NumPy ufuncs_ and is able to generate equivalent native code for many of them.
NumPy arrays are directly supported in Numba. Access to NumPy arrays is very efficient, as indexing is lowered to direct memory accesses when possible.
Numba is able to generate ufuncs_ and gufuncs_. This means that it is possible to implement ufuncs and gufuncs within Python, getting speeds comparable to that of ufuncs/gufuncs implemented in C extension modules using the NumPy C API.

.. _NumPy: http://www.numpy.org/ .. _ufuncs: http://docs.scipy.org/doc/numpy/reference/ufuncs.html .. _gufuncs: http://docs.scipy.org/doc/numpy/reference/c-api.generalized-ufuncs.html

The following sections focus on the NumPy features supported in :term:nopython mode, unless otherwise stated.

Scalar types

Numba supports the following NumPy scalar types:

Integers: all integers of either signedness, and any width up to 64 bits
Booleans
Real numbers: single-precision (32-bit) and double-precision (64-bit) reals
Complex numbers: single-precision (2x32-bit) and double-precision (2x64-bit) complex numbers
Datetimes and timestamps: of any unit
Character sequences (but no operations are available on them)
Structured scalars: structured scalars made of any of the types above and arrays of the types above

The following scalar types and features are not supported:

Arbitrary Python objects
Half-precision and extended-precision real and complex numbers
Nested structured scalars the fields of structured scalars may not contain other structured scalars

The operations supported on NumPy scalars are almost the same as on the equivalent built-in types such as int or float. You can use a type's constructor to convert from a different type or width. In addition you can use the view(np.<dtype>) method to bitcast all int and float types within the same width. However, you must define the scalar using a NumPy constructor within a jitted function. For example, the following will work:

.. code:: pycon

>>> import numpy as np
>>> from numba import njit
>>> @njit
... def bitcast():
...     i = np.int64(-1)
...     print(i.view(np.uint64))
...
>>> bitcast()
18446744073709551615

Whereas the following will not work:

.. code:: pycon

>>> import numpy as np
>>> from numba import njit
>>> @njit
... def bitcast(i):
...     print(i.view(np.uint64))
...
>>> bitcast(np.int64(-1))
---------------------------------------------------------------------------
TypingError                               Traceback (most recent call last)
    ...
TypingError: Failed in nopython mode pipeline (step: ensure IR is legal prior to lowering)
'view' can only be called on NumPy dtypes, try wrapping the variable with 'np.<dtype>()'

File "<ipython-input-3-fc40aaab84c4>", line 3:
def bitcast(i):
    print(i.view(np.uint64))

Structured scalars support attribute getting and setting, as well as member lookup using constant strings. Strings stored in a local or global tuple are considered constant strings and can be used for member lookup.

.. literalinclude:: ../../../numba/tests/doc_examples/test_rec_array.py :language: python :start-after: magictoken.ex_rec_arr_const_index.begin :end-before: magictoken.ex_rec_arr_const_index.end :dedent: 8

It is also possible to use local or global tuples together with literal_unroll:

.. literalinclude:: ../../../numba/tests/doc_examples/test_rec_array.py :language: python :start-after: magictoken.ex_rec_arr_lit_unroll_index.begin :end-before: magictoken.ex_rec_arr_lit_unroll_index.end :dedent: 8

Record subtyping

.. warning:: This is an experimental feature.

Numba allows width subtyping of structured scalars. For example, dtype([('a', 'f8'), ('b', 'i8')]) will be considered a subtype of dtype([('a', 'f8')], because the second is a strict subset of the first, i.e. field a is of the same type and is in the same position in both types. The subtyping relationship will matter in cases where compilation for a certain input is not allowed, but the input is a subtype of another, allowed type.

.. code-block:: python

import numpy as np
from numba import njit, typeof
from numba.core import types
record1 = np.array([1], dtype=[('a', 'f8')])[0]
record2 = np.array([(2,3)], dtype=[('a', 'f8'), ('b', 'f8')])[0]

@njit(types.float64(typeof(record1)))
def foo(rec):
    return rec['a']

foo(record1)
foo(record2)

Without subtyping the last line would fail. With subtyping, no new compilation will be triggered, but the compiled function for record1 will be used for record2.

.. seealso:: NumPy scalars reference.

Array types

NumPy arrays of any of the scalar types above are supported, regardless of the shape or layout.

.. note:: NumPy MaskedArrays are not supported.

Array access

Arrays support normal iteration. Full basic indexing and slicing is supported along with passing None / np.newaxis as indices for additional resulting dimensions. A subset of advanced indexing is also supported: only one advanced index is allowed, and it has to be a one-dimensional array (it can be combined with an arbitrary number of basic indices as well).

.. seealso:: NumPy indexing reference.

.. _structured-array-access:

Structured array access

Numba presently supports accessing fields of individual elements in structured arrays by attribute as well as by getting and setting. This goes slightly beyond the NumPy API, which only allows accessing fields by getting and setting. For example:

.. code:: python

from numba import njit import numpy as np

record_type = np.dtype([("ival", np.int32), ("fval", np.float64)], align=True)

def f(rec): value = 2.5 rec[0].ival = int(value) rec[0].fval = value return rec

arr = np.ones(1, dtype=record_type)

cfunc = njit(f)

Works

print(cfunc(arr))

Does not work

print(f(arr))

The above code results in the output:

.. code:: none

[(2, 2.5)] Traceback (most recent call last): File "repro.py", line 22, in print(f(arr)) File "repro.py", line 9, in f rec[0].ival = int(value) AttributeError: 'numpy.void' object has no attribute 'ival'

The Numba-compiled version of the function executes, but the pure Python version raises an error because of the unsupported use of attribute access.

.. note:: This behavior will eventually be deprecated and removed.

Attributes

The following attributes of NumPy arrays are supported:

:attr:~numpy.ndarray.dtype
:attr:~numpy.ndarray.flags
:attr:~numpy.ndarray.flat
:attr:~numpy.ndarray.itemsize
:attr:~numpy.ndarray.nbytes
:attr:~numpy.ndarray.ndim
:attr:~numpy.ndarray.shape
:attr:~numpy.ndarray.size
:attr:~numpy.ndarray.strides
:attr:~numpy.ndarray.T
:attr:~numpy.ndarray.real
:attr:~numpy.ndarray.imag

The flags object ''''''''''''''''''''

The object returned by the :attr:~numpy.ndarray.flags attribute supports the contiguous, c_contiguous and f_contiguous attributes.

The flat object '''''''''''''''''''

The object returned by the :attr:~numpy.ndarray.flat attribute supports iteration and indexing, but be careful: indexing is very slow on non-C-contiguous arrays.

The real and imag attributes ''''''''''''''''''''''''''''''''''''

NumPy supports these attributes regardless of the dtype but Numba chooses to limit their support to avoid potential user error. For numeric dtypes, Numba follows NumPy's behavior. The :attr:~numpy.ndarray.real attribute returns a view of the real part of the complex array and it behaves as an identity function for other numeric dtypes. The :attr:~numpy.ndarray.imag attribute returns a view of the imaginary part of the complex array and it returns a zero array with the same shape and dtype for other numeric dtypes. For non-numeric dtypes, including all structured/record dtypes, using these attributes will result in a compile-time (TypingError) error. This behavior differs from NumPy's but it is chosen to avoid the potential confusion with field names that overlap these attributes.

Calculation

The following methods of NumPy arrays are supported in their basic form (without any optional arguments):

:meth:~numpy.ndarray.all
:meth:~numpy.ndarray.any
:meth:~numpy.ndarray.clip
:meth:~numpy.ndarray.conj
:meth:~numpy.ndarray.conjugate
:meth:~numpy.ndarray.cumprod
:meth:~numpy.ndarray.cumsum
:meth:~numpy.ndarray.max
:meth:~numpy.ndarray.mean
:meth:~numpy.ndarray.min
:meth:~numpy.ndarray.nonzero
:meth:~numpy.ndarray.prod
:meth:~numpy.ndarray.std
:meth:~numpy.ndarray.take
:meth:~numpy.ndarray.var

The corresponding top-level NumPy functions (such as :func:numpy.prod) are similarly supported.

Other methods

The following methods of NumPy arrays are supported:

:meth:~numpy.ndarray.argmax (axis keyword argument supported).
:meth:~numpy.ndarray.argmin (axis keyword argument supported).
:func:numpy.argpartition (only the 2 first arguments)
:meth:~numpy.ndarray.argsort (kind key word argument supported for values 'quicksort' and 'mergesort')
:meth:~numpy.ndarray.astype (only the 1-argument form)
:meth:~numpy.ndarray.copy (without arguments)
:meth:~numpy.ndarray.dot (only the 1-argument form)
:meth:~numpy.ndarray.flatten (no order argument; 'C' order only)
:meth:~numpy.ndarray.item (without arguments)
:meth:~numpy.ndarray.itemset (only the 1-argument form)
:meth:~numpy.ndarray.ptp (without arguments)
:meth:~numpy.ndarray.ravel (no order argument; 'C' order only)
:meth:~numpy.ndarray.repeat (no axis argument)
:meth:~numpy.ndarray.reshape (only the 1-argument form)
:meth:~numpy.ndarray.sort (without arguments)
:meth:~numpy.ndarray.sum (with or without the axis and/or dtype arguments.)
- axis only supports integer values.
- If the axis argument is a compile-time constant, all valid values are supported. An out-of-range value will result in a LoweringError at compile-time.
- If the axis argument is not a compile-time constant, only values from 0 to 3 are supported. An out-of-range value will result in a runtime exception.
- All numeric dtypes are supported in the dtype parameter. timedelta arrays can be used as input arrays but timedelta is not supported as dtype parameter.
- When a dtype is given, it determines the type of the internal accumulator. When it is not, the selection is made automatically based on the input array's dtype, mostly following the same rules as NumPy. However, on 64-bit Windows, Numba uses a 64-bit accumulator for integer inputs (int64 for int32 inputs and uint64 for uint32 inputs), while NumPy would use a 32-bit accumulator in those cases.
:meth:~numpy.ndarray.transpose
:meth:~numpy.ndarray.view (only the 1-argument form)
:meth:~numpy.ndarray.__contains__

Where applicable, the corresponding top-level NumPy functions (such as :func:numpy.argmax) are similarly supported.

.. warning:: Sorting may be slightly slower than NumPy's implementation.

Functions

Linear algebra

Basic linear algebra is supported on 1-D and 2-D contiguous arrays of floating-point and complex numbers:

:func:numpy.dot
:func:numpy.kron ('C' and 'F' order only)
:func:numpy.outer
:func:numpy.trace (only the first argument).
:func:numpy.vdot
On Python 3.5 and above, the matrix multiplication operator from :pep:465 (i.e. a @ b where a and b are 1-D or 2-D arrays).
:func:numpy.linalg.cholesky
:func:numpy.linalg.cond (only non string values in p).
:func:numpy.linalg.det
:func:numpy.linalg.eig (only running with data that does not cause a domain change is supported e.g. real input -> real output, complex input -> complex output).
:func:numpy.linalg.eigh (only the first argument).
:func:numpy.linalg.eigvals (only running with data that does not cause a domain change is supported e.g. real input -> real output, complex input -> complex output).
:func:numpy.linalg.eigvalsh (only the first argument).
:func:numpy.linalg.inv
:func:numpy.linalg.lstsq
:func:numpy.linalg.matrix_power
:func:numpy.linalg.matrix_rank
:func:numpy.linalg.norm (only the 2 first arguments and only non string values in ord).
:func:numpy.linalg.pinv
:func:numpy.linalg.qr (only the first argument).
:func:numpy.linalg.slogdet
:func:numpy.linalg.solve
:func:numpy.linalg.svd (only the 2 first arguments).

.. note:: The implementation of these functions needs SciPy to be installed.

Reductions

The following reduction functions are supported:

:func:numpy.diff (only the 2 first arguments)
:func:numpy.amin (only the first argument, also aliased as np.min)
:func:numpy.amax (only the first argument, also aliased as np.max)
:func:numpy.median (only the first argument)
:func:numpy.nancumprod (only the first argument)
:func:numpy.nancumsum (only the first argument)
:func:numpy.nanmax (only the first argument)
:func:numpy.nanmean (only the first argument)
:func:numpy.nanmedian (only the first argument)
:func:numpy.nanmin (only the first argument)
:func:numpy.nanpercentile (only the 2 first arguments, complex dtypes unsupported)
:func:numpy.nanquantile (only the 2 first arguments, complex dtypes unsupported)
:func:numpy.nanprod (only the first argument)
:func:numpy.nanstd (only the first argument)
:func:numpy.nansum (only the first argument)
:func:numpy.nanvar (only the first argument)
:func:numpy.percentile (only the 2 first arguments, complex dtypes unsupported)
:func:numpy.quantile (only the 2 first arguments, complex dtypes unsupported)

Polynomials

The following polynomial classes are supported:

:class:numpy.polynomial.polynomial.Polynomial (only the first three arguments)

The following polynomial functions are supported:

:func:numpy.polynomial.polynomial.polyadd()
:func:numpy.polynomial.polynomial.polydiv()
:func:numpy.polynomial.polynomial.polyint() (only the 2 first arguments)
:func:numpy.polynomial.polynomial.polymul()
:func:numpy.polynomial.polynomial.polysub()
:func:numpy.polynomial.polynomial.polyval() (the argument tensor must be a boolean constant)
:func:numpy.polynomial.polyutils.as_series()
:func:numpy.polynomial.polyutils.trimseq()

Other functions

The following top-level functions are supported:

:func:numpy.allclose
:func:numpy.append
:func:numpy.arange
:func:numpy.argsort (kind key word argument supported for values 'quicksort' and 'mergesort')
:func:numpy.argwhere
:func:numpy.around
:func:numpy.array (only the 2 first arguments)
:func:numpy.array_equal
:func:numpy.array_split
:func:numpy.asarray (only the 2 first arguments)
:func:numpy.asarray_chkfinite (only the 2 first arguments)
:func:numpy.ascontiguousarray (only the first argument)
:func:numpy.asfarray
:func:numpy.asfortranarray (only the first argument)
:func:numpy.atleast_1d
:func:numpy.atleast_2d
:func:numpy.atleast_3d
:func:numpy.bartlett
:func:numpy.bincount
:func:numpy.blackman
:func:numpy.broadcast_to (only the 2 first arguments)
:func:numpy.broadcast_arrays (only the first argument)
:func:numpy.broadcast_shapes
:func:numpy.column_stack
:func:numpy.concatenate (only supports tuple arguments)
:func:numpy.convolve (all arguments)
:func:numpy.copy (only the first argument)
:func:numpy.corrcoef (only the 3 first arguments, requires SciPy)
:func:numpy.correlate (all arguments)
:func:numpy.count_nonzero (axis only supports scalar values)
:func:numpy.cov (only the 5 first arguments)
:func:numpy.cross (only the 2 first arguments; at least one of the input arrays should have shape[-1] == 3)
- If shape[-1] == 2 for both inputs, please replace your :func:numpy.cross call with :func:numba.np.extensions.cross2d.
:func:numpy.delete (only the 2 first arguments)
:func:numpy.diag
:func:numpy.diagflat
:func:numpy.digitize
:func:numpy.dsplit
:func:numpy.dstack
:func:numpy.dtype (only the first argument)
:func:numpy.ediff1d
:func:numpy.empty (only the 2 first arguments)
:func:numpy.empty_like (only the 2 first arguments)
:func:numpy.expand_dims
:func:numpy.extract
:func:numpy.eye
:func:numpy.fill_diagonal
:func:numpy.flatten (no order argument; 'C' order only)
:func:numpy.flatnonzero
:func:numpy.flip (no axis argument)
:func:numpy.fliplr
:func:numpy.flipud
:func:numpy.frombuffer (only the 2 first arguments)
:func:numpy.full (only the 3 first arguments)
:func:numpy.full_like (only the 3 first arguments)
:func:numpy.geomspace (only the 3 first arguments)
:func:numpy.hamming
:func:numpy.hanning
:func:numpy.histogram (only the 3 first arguments)
:func:numpy.hsplit
:func:numpy.hstack
:func:numpy.identity
:func:numpy.indices (only the first argument)
:func:numpy.isclose
:func:numpy.kaiser
:func:numpy.iscomplex
:func:numpy.iscomplexobj
:func:numpy.isneginf
:func:numpy.isposinf
:func:numpy.isreal
:func:numpy.isrealobj
:func:numpy.isscalar
:func:numpy.interp (only the 3 first arguments)
:func:numpy.intersect1d (only first 2 arguments, ar1 and ar2)
:func:numpy.linspace (only the 3-argument form)
:func:numpy.logspace (only the 3 first arguments)
:func:numpy.nan_to_num (only the 3 first arguments)
:class:numpy.ndenumerate
:class:numpy.ndindex
:class:numpy.nditer (only the first argument)
:func:numpy.ones (only the 2 first arguments)
:func:numpy.ones_like (only the 2 first arguments)
:func:numpy.partition (only the 2 first arguments)
:func:numpy.ptp (only the first argument)
:func:numpy.ravel (no order argument; 'C' order only)
:func:numpy.repeat (no axis argument)
:func:numpy.reshape (no order argument; 'C' order only)
:func:numpy.resize
:func:numpy.roll (only the 2 first arguments; second argument shift must be an integer)
:func:numpy.roots
:func:numpy.rot90 (only the 2 first arguments)
:func:numpy.round_
:func:numpy.row_stack
:func:numpy.searchsorted (only the 3 first arguments)
:func:numpy.select (only using homogeneous lists or tuples for the first two arguments, condlist and choicelist). Additionally, these two arguments can only contain arrays (unlike NumPy that also accepts tuples).
:func:numpy.shape
:func:numpy.sinc
:func:numpy.sort (no optional arguments, quicksort accepts multi-dimensional array and sorts its last axis).
:func:numpy.split
:func:numpy.stack (only the first two arguments are supported)
:func:numpy.swapaxes
:func:numpy.take (only the 2 first arguments)
:func:numpy.take_along_axis (the axis argument must be a literal value)
:func:numpy.transpose
:func:numpy.trapz (only the 3 first arguments)
:func:numpy.tri (only the 3 first arguments; third argument k must be an integer)
:func:numpy.tril (second argument k must be an integer)
:func:numpy.tril_indices (all arguments must be integer)
:func:numpy.tril_indices_from (second argument k must be an integer)
:func:numpy.trim_zeros (for NumPy array arguments only)
:func:numpy.triu (second argument k must be an integer)
:func:numpy.triu_indices (all arguments must be integer)
:func:numpy.triu_indices_from (second argument k must be an integer)
:func:numpy.union1d (For unicode arrays, only supports arrays of the same dtype)
:func:numpy.unique (only the first argument)
:func:numpy.unwrap (third argument axis must equal -1)
:func:numpy.vander
:func:numpy.vsplit
:func:numpy.vstack
:func:numpy.where
:func:numpy.zeros (only the 2 first arguments)
:func:numpy.zeros_like (only the 2 first arguments)

The following constructors are supported, both with a numeric input (to construct a scalar) or a sequence (to construct an array):

:class:numpy.bool_
:class:numpy.complex64
:class:numpy.complex128
:class:numpy.float32
:class:numpy.float64
:class:numpy.int8
:class:numpy.int16
:class:numpy.int32
:class:numpy.int64
:class:numpy.intc
:class:numpy.intp
:class:numpy.uint8
:class:numpy.uint16
:class:numpy.uint32
:class:numpy.uint64
:class:numpy.uintc
:class:numpy.uintp

The following machine parameter classes are supported, with all purely numerical attributes:

:class:numpy.iinfo
:class:numpy.finfo (machar attribute not supported)
:class:numpy.MachAr (with no arguments to the constructor)

Literal arrays

.. XXX should this part of the user's guide?

Neither Python nor Numba has actual array literals, but you can construct arbitrary arrays by calling :func:numpy.array on a nested tuple::

a = numpy.array(((a, b, c), (d, e, f)))

(nested lists are not yet supported by Numba)

Modules

.. _numpy-random:

`random`

Generator Objects ''''''''''''''''' Numba supports :py:class:numpy.random.Generator() objects. As of version 0.56, users can pass individual NumPy :py:class:Generator objects into Numba functions and use their methods inside the functions. The same algorithms are used as NumPy for random number generation hence maintaining parity between the random number generated using NumPy and Numba under identical arguments (also the same documentation notes as NumPy :py:class:Generator methods apply). The current Numba support for :py:class:Generator is not thread-safe, hence we do not recommend using :py:class:Generator methods in methods with parallel execution logic.

.. note:: NumPy's :py:class:Generator objects rely on :py:class:BitGenerator to manage state and generate the random bits, which are then transformed into random values from useful distributions. Numba will unbox the :py:class:Generator objects and will maintain a reference to the underlying :py:class:BitGenerator objects using NumPy's ctypes interface bindings. Hence :py:class:Generator objects can cross the JIT boundary and their functions be used within Numba-Jit code. Note that since only references to :py:class:BitGenerator objects are maintained, any change to the state of a particular :py:class:Generator object outside Numba code would affect the state of :py:class:Generator inside the Numba code.

.. literalinclude:: ../../../numba/tests/doc_examples/test_numpy_generators.py :language: python :start-after: magictoken.npgen_usage.begin :end-before: magictoken.npgen_usage.end :dedent: 8

The following :py:class:Generator methods are supported:

:func:numpy.random.Generator().beta()
:func:numpy.random.Generator().chisquare()
:func:numpy.random.Generator().exponential()
:func:numpy.random.Generator().f()
:func:numpy.random.Generator().gamma()
:func:numpy.random.Generator().geometric()
:func:numpy.random.Generator().integers() (Both low and high are required arguments. Array values for low and high are currently not supported.)
:func:numpy.random.Generator().laplace()
:func:numpy.random.Generator().logistic()
:func:numpy.random.Generator().lognormal()
:func:numpy.random.Generator().logseries() (Accepts float values as well as data types that cast to floats. Array values for p are currently not supported.)
:func:numpy.random.Generator().negative_binomial()
:func:numpy.random.Generator().noncentral_chisquare() (Accepts float values as well as data types that cast to floats. Array values for dfnum and nonc are currently not supported.)
:func:numpy.random.Generator().noncentral_f() (Accepts float values as well as data types that cast to floats. Array values for dfnum, dfden and nonc are currently not supported.)
:func:numpy.random.Generator().normal()
:func:numpy.random.Generator().pareto()
:func:numpy.random.Generator().permutation() (Only accepts NumPy ndarrays and integers.)
:func:numpy.random.Generator().poisson()
:func:numpy.random.Generator().power()
:func:numpy.random.Generator().random()
:func:numpy.random.Generator().rayleigh()
:func:numpy.random.Generator().shuffle() (Only accepts NumPy ndarrays.)
:func:numpy.random.Generator().standard_cauchy()
:func:numpy.random.Generator().standard_exponential()
:func:numpy.random.Generator().standard_gamma()
:func:numpy.random.Generator().standard_normal()
:func:numpy.random.Generator().standard_t()
:func:numpy.random.Generator().triangular()
:func:numpy.random.Generator().uniform()
:func:numpy.random.Generator().wald()
:func:numpy.random.Generator().weibull()
:func:numpy.random.Generator().zipf()

.. note:: Due to instruction selection differences across compilers, there may be discrepancies, when compared to NumPy, in the order of 1000s of ULPs on 32-bit architectures as well as linux-aarch64 and linux- ppc64le platforms. For Linux-x86_64, Windows-x86_64 and macOS these discrepancies are less pronounced (order of 10s of ULPs) but are not guaranteed to follow the exception pattern and may increase in some cases.

The differences are unlikely to impact the "quality" of the random number generation as they occur through changes in rounding that happen when fused-multiply-add is used instead of multiplication followed by addition.

RandomState and legacy Random number generation '''''''''''''''''''''''''''''''''''''''''''''''

Numba supports top-level functions from the numpy.random module, but does not allow you to create individual RandomState instances. The same algorithms are used as for :ref:the standard random module <pysupported-random> (and therefore the same notes apply), but with an independent internal state: seeding or drawing numbers from one generator won't affect the other.

The following functions are supported.

Initialization ''''''''''''''

:func:numpy.random.seed: with an integer argument only

.. warning:: Calling :func:numpy.random.seed from interpreted code (including from :term:object mode code) will seed the NumPy random generator, not the Numba random generator. To seed the Numba random generator, see the example below.

.. code-block:: python

from numba import njit import numpy as np

@njit def seed(a): np.random.seed(a)

@njit def rand(): return np.random.rand()

Incorrect seeding

np.random.seed(1234) print(rand())

Correct seeding

seed(1234) print(rand())

Simple random data ''''''''''''''''''

:func:numpy.random.rand
:func:numpy.random.randint (only the first two arguments)
:func:numpy.random.randn
:func:numpy.random.random
:func:numpy.random.random_sample
:func:numpy.random.ranf
:func:numpy.random.sample

Permutations ''''''''''''

:func:numpy.random.choice: the optional p argument (probabilities array) is not supported
:func:numpy.random.permutation
:func:numpy.random.shuffle: the sequence argument must be a one-dimension NumPy array or buffer-providing object (such as a :class:bytearray or :class:array.array)

Distributions '''''''''''''

The following functions support all arguments.

:func:numpy.random.beta
:func:numpy.random.binomial
:func:numpy.random.chisquare
:func:numpy.random.dirichlet
:func:numpy.random.exponential
:func:numpy.random.f
:func:numpy.random.gamma
:func:numpy.random.geometric
:func:numpy.random.gumbel
:func:numpy.random.hypergeometric
:func:numpy.random.laplace
:func:numpy.random.logistic
:func:numpy.random.lognormal
:func:numpy.random.logseries
:func:numpy.random.multinomial
:func:numpy.random.negative_binomial
:func:numpy.random.noncentral_chisquare
:func:numpy.random.normal
:func:numpy.random.pareto
:func:numpy.random.poisson
:func:numpy.random.power
:func:numpy.random.rayleigh
:func:numpy.random.standard_cauchy
:func:numpy.random.standard_exponential
:func:numpy.random.standard_gamma
:func:numpy.random.standard_normal
:func:numpy.random.standard_t
:func:numpy.random.triangular
:func:numpy.random.uniform
:func:numpy.random.vonmises
:func:numpy.random.wald
:func:numpy.random.weibull
:func:numpy.random.zipf

.. note:: Calling :func:numpy.random.seed from non-Numba code (or from :term:object mode code) will seed the NumPy random generator, not the Numba random generator.

.. note:: Since version 0.28.0, the generator is thread-safe and fork-safe. Each thread and each process will produce independent streams of random numbers.

`stride_tricks`

The following functions from the :mod:numpy.lib.stride_tricks module are supported:

:func:~numpy.lib.stride_tricks.as_strided (the strides argument is mandatory, the subok argument is not supported)
:func:~numpy.lib.stride_tricks.sliding_window_view (the subok argument is not supported, the writeable argument is not supported with the returned view always being writeable)

.. _supported_ufuncs:

Standard ufuncs

One objective of Numba is having all the standard ufuncs in NumPy understood by Numba. When a supported ufunc is found when compiling a function, Numba maps the ufunc to equivalent native code. This allows the use of those ufuncs in Numba code that gets compiled in :term:nopython mode.

Limitations

Right now, only a selection of the standard ufuncs work in :term:nopython mode. Following is a list of the different standard ufuncs that Numba is aware of, sorted in the same way as in the NumPy documentation.