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| 1 | +# Copyright (c) Brockmann Consult GmbH, 2025 |
| 2 | +# License: MIT |
| 3 | + |
| 4 | +""" |
| 5 | +This module provides random number generators. |
| 6 | +""" |
| 7 | + |
| 8 | +import numpy as np |
| 9 | +from numpy.random import BitGenerator |
| 10 | +from numpy.random import Generator |
| 11 | +from overrides import overrides |
| 12 | + |
| 13 | +from .interface.generating import Generating |
| 14 | +from .interface.generating import Normal |
| 15 | +from .interface.generating import Uniform |
| 16 | +from .interface.generating import Univariate |
| 17 | + |
| 18 | + |
| 19 | +def default_bit_generator( |
| 20 | + seed: int | np.ndarray | None = None, |
| 21 | +) -> BitGenerator: |
| 22 | + """ |
| 23 | + Returns the default bit generator. |
| 24 | +
|
| 25 | + :param seed: The seed. |
| 26 | + :return: The default bit generator. |
| 27 | + """ |
| 28 | + from numpy.random import PCG64DXSM |
| 29 | + |
| 30 | + return PCG64DXSM(seed) |
| 31 | + |
| 32 | + |
| 33 | +def default_generator(seed) -> Generator: |
| 34 | + """ |
| 35 | + Returns the default generator. |
| 36 | +
|
| 37 | + :param seed: The seed. |
| 38 | + :return: The default generator. |
| 39 | + """ |
| 40 | + return Generator( |
| 41 | + seed |
| 42 | + if isinstance(seed, BitGenerator) |
| 43 | + else default_bit_generator(seed) |
| 44 | + ) |
| 45 | + |
| 46 | + |
| 47 | +class DefaultGenerator(Generating): |
| 48 | + """The default random number generator.""" |
| 49 | + |
| 50 | + _g: Generator |
| 51 | + |
| 52 | + def __init__(self, seed: int | np.ndarray | BitGenerator | None = None): |
| 53 | + """ |
| 54 | + Creates a new random number generator. |
| 55 | +
|
| 56 | + :param seed: The seed. |
| 57 | + """ |
| 58 | + self._g = default_generator(seed) |
| 59 | + |
| 60 | + @overrides |
| 61 | + def random(self) -> int: |
| 62 | + return self._g.integers(0x8000000000000000) |
| 63 | + |
| 64 | + |
| 65 | +class DefaultUniform(Uniform): |
| 66 | + """The default uniform random deviate.""" |
| 67 | + |
| 68 | + _g: Generator |
| 69 | + |
| 70 | + def __init__(self, seed: int | np.ndarray | BitGenerator | None = None): |
| 71 | + """ |
| 72 | + Creates a new random variate. |
| 73 | +
|
| 74 | + :param seed: The seed. |
| 75 | + """ |
| 76 | + self._g = default_generator(seed) |
| 77 | + |
| 78 | + @overrides |
| 79 | + def get(self, i: int) -> Univariate: |
| 80 | + return self |
| 81 | + |
| 82 | + @overrides |
| 83 | + def random(self) -> float: |
| 84 | + return self._g.random() |
| 85 | + |
| 86 | + @overrides |
| 87 | + def randoms(self, randoms: np.ndarray) -> np.ndarray: |
| 88 | + self._g.random(out=randoms) |
| 89 | + return randoms |
| 90 | + |
| 91 | + |
| 92 | +class DefaultNormal(Normal): |
| 93 | + """The default normal random variate.""" |
| 94 | + |
| 95 | + _g: Generator |
| 96 | + |
| 97 | + def __init__(self, seed: int | np.ndarray | BitGenerator | None = None): |
| 98 | + """ |
| 99 | + Creates a new random variate. |
| 100 | +
|
| 101 | + :param seed: The seed. |
| 102 | + """ |
| 103 | + self._g = default_generator(seed) |
| 104 | + |
| 105 | + @overrides |
| 106 | + def get(self, i: int) -> Univariate: |
| 107 | + return self |
| 108 | + |
| 109 | + @overrides |
| 110 | + def random(self) -> float: |
| 111 | + return self._g.standard_normal() |
| 112 | + |
| 113 | + @overrides |
| 114 | + def randoms(self, randoms: np.ndarray) -> np.ndarray: |
| 115 | + self._g.standard_normal(out=randoms) |
| 116 | + return randoms |
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