diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/numpy/random/_examples/cython/extending_distributions.pyx')
-rw-r--r-- | .venv/lib/python3.12/site-packages/numpy/random/_examples/cython/extending_distributions.pyx | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/numpy/random/_examples/cython/extending_distributions.pyx b/.venv/lib/python3.12/site-packages/numpy/random/_examples/cython/extending_distributions.pyx new file mode 100644 index 00000000..d908e92d --- /dev/null +++ b/.venv/lib/python3.12/site-packages/numpy/random/_examples/cython/extending_distributions.pyx @@ -0,0 +1,117 @@ +#!/usr/bin/env python3 +#cython: language_level=3 +""" +This file shows how the to use a BitGenerator to create a distribution. +""" +import numpy as np +cimport numpy as np +cimport cython +from cpython.pycapsule cimport PyCapsule_IsValid, PyCapsule_GetPointer +from libc.stdint cimport uint16_t, uint64_t +from numpy.random cimport bitgen_t +from numpy.random import PCG64 +from numpy.random.c_distributions cimport ( + random_standard_uniform_fill, random_standard_uniform_fill_f) + + +@cython.boundscheck(False) +@cython.wraparound(False) +def uniforms(Py_ssize_t n): + """ + Create an array of `n` uniformly distributed doubles. + A 'real' distribution would want to process the values into + some non-uniform distribution + """ + cdef Py_ssize_t i + cdef bitgen_t *rng + cdef const char *capsule_name = "BitGenerator" + cdef double[::1] random_values + + x = PCG64() + capsule = x.capsule + # Optional check that the capsule if from a BitGenerator + if not PyCapsule_IsValid(capsule, capsule_name): + raise ValueError("Invalid pointer to anon_func_state") + # Cast the pointer + rng = <bitgen_t *> PyCapsule_GetPointer(capsule, capsule_name) + random_values = np.empty(n, dtype='float64') + with x.lock, nogil: + for i in range(n): + # Call the function + random_values[i] = rng.next_double(rng.state) + randoms = np.asarray(random_values) + + return randoms + +# cython example 2 +@cython.boundscheck(False) +@cython.wraparound(False) +def uint10_uniforms(Py_ssize_t n): + """Uniform 10 bit integers stored as 16-bit unsigned integers""" + cdef Py_ssize_t i + cdef bitgen_t *rng + cdef const char *capsule_name = "BitGenerator" + cdef uint16_t[::1] random_values + cdef int bits_remaining + cdef int width = 10 + cdef uint64_t buff, mask = 0x3FF + + x = PCG64() + capsule = x.capsule + if not PyCapsule_IsValid(capsule, capsule_name): + raise ValueError("Invalid pointer to anon_func_state") + rng = <bitgen_t *> PyCapsule_GetPointer(capsule, capsule_name) + random_values = np.empty(n, dtype='uint16') + # Best practice is to release GIL and acquire the lock + bits_remaining = 0 + with x.lock, nogil: + for i in range(n): + if bits_remaining < width: + buff = rng.next_uint64(rng.state) + random_values[i] = buff & mask + buff >>= width + + randoms = np.asarray(random_values) + return randoms + +# cython example 3 +def uniforms_ex(bit_generator, Py_ssize_t n, dtype=np.float64): + """ + Create an array of `n` uniformly distributed doubles via a "fill" function. + + A 'real' distribution would want to process the values into + some non-uniform distribution + + Parameters + ---------- + bit_generator: BitGenerator instance + n: int + Output vector length + dtype: {str, dtype}, optional + Desired dtype, either 'd' (or 'float64') or 'f' (or 'float32'). The + default dtype value is 'd' + """ + cdef Py_ssize_t i + cdef bitgen_t *rng + cdef const char *capsule_name = "BitGenerator" + cdef np.ndarray randoms + + capsule = bit_generator.capsule + # Optional check that the capsule if from a BitGenerator + if not PyCapsule_IsValid(capsule, capsule_name): + raise ValueError("Invalid pointer to anon_func_state") + # Cast the pointer + rng = <bitgen_t *> PyCapsule_GetPointer(capsule, capsule_name) + + _dtype = np.dtype(dtype) + randoms = np.empty(n, dtype=_dtype) + if _dtype == np.float32: + with bit_generator.lock: + random_standard_uniform_fill_f(rng, n, <float*>np.PyArray_DATA(randoms)) + elif _dtype == np.float64: + with bit_generator.lock: + random_standard_uniform_fill(rng, n, <double*>np.PyArray_DATA(randoms)) + else: + raise TypeError('Unsupported dtype %r for random' % _dtype) + return randoms + |