# -*- coding: utf-8 -*-
"""
GStools subpackage providing tools for random sampling.
.. currentmodule:: gstools.random.tools
The following classes are provided
.. autosummary::
MasterRNG
dist_gen
"""
from scipy.stats import rv_continuous
import numpy.random as rand
__all__ = ["MasterRNG", "dist_gen"]
class MasterRNG:
"""Master random number generator for generating seeds.
Parameters
----------
seed : :class:`int` or :any:`None`, optional
The seed of the master RNG, if ``None``,
a random seed is used. Default: ``None``
"""
def __init__(self, seed):
self._seed = seed
self._master_rng_fct = rand.RandomState(seed)
self._master_rng = lambda: self._master_rng_fct.randint(1, 2 ** 16)
def __call__(self):
"""Return a random seed."""
return self._master_rng()
@property # pragma: no cover
def seed(self):
""":class:`int`: Seed of the master RNG.
The setter property not only saves the new seed, but also creates
a new master RNG function with the new seed.
"""
return self._seed
def __str__(self):
"""Return String representation."""
return self.__repr__()
def __repr__(self):
"""Return String representation."""
return "RNG(seed={})".format(self.seed)
def dist_gen(pdf_in=None, cdf_in=None, ppf_in=None, **kwargs):
"""Distribution Factory.
Parameters
----------
pdf_in : :any:`callable` or :any:`None`, optional
Proprobability distribution function of the given distribution, that
takes a single argument
Default: ``None``
cdf_in : :any:`callable` or :any:`None`, optional
Cumulative distribution function of the given distribution, that
takes a single argument
Default: ``None``
ppf_in : :any:`callable` or :any:`None`, optional
Percent point function of the given distribution, that
takes a single argument
Default: ``None``
**kwargs
Keyword-arguments forwarded to :any:`scipy.stats.rv_continuous`.
Returns
-------
dist : :class:`scipy.stats.rv_continuous`
The constructed distribution.
Notes
-----
At least pdf or cdf needs to be given.
"""
if ppf_in is None:
if pdf_in is not None and cdf_in is None:
return DistPdf(pdf_in, **kwargs)
if pdf_in is None and cdf_in is not None:
return DistCdf(cdf_in, **kwargs)
if pdf_in is not None and cdf_in is not None:
return DistPdfCdf(pdf_in, cdf_in, **kwargs)
raise ValueError("Either pdf or cdf must be given")
else:
if pdf_in is not None and cdf_in is None:
return DistPdfPpf(pdf_in, ppf_in, **kwargs)
if pdf_in is None and cdf_in is not None:
return DistCdfPpf(cdf_in, ppf_in, **kwargs)
if pdf_in is not None and cdf_in is not None:
return DistPdfCdfPpf(pdf_in, cdf_in, ppf_in, **kwargs)
raise ValueError("pdf or cdf must be given along with the ppf")
class DistPdf(rv_continuous):
"""Generate distribution from pdf."""
def __init__(self, pdf_in, **kwargs):
self.pdf_in = pdf_in
super().__init__(**kwargs)
def _pdf(self, x, *args):
return self.pdf_in(x)
class DistCdf(rv_continuous):
"""Generate distribution from cdf."""
def __init__(self, cdf_in, **kwargs):
self.cdf_in = cdf_in
super().__init__(**kwargs)
def _cdf(self, x, *args):
return self.cdf_in(x)
class DistPdfCdf(rv_continuous):
"""Generate distribution from pdf and cdf."""
def __init__(self, pdf_in, cdf_in, **kwargs):
self.pdf_in = pdf_in
self.cdf_in = cdf_in
super().__init__(**kwargs)
def _pdf(self, x, *args):
return self.pdf_in(x)
def _cdf(self, x, *args):
return self.cdf_in(x)
class DistPdfPpf(rv_continuous):
"""Generate distribution from pdf and ppf."""
def __init__(self, pdf_in, ppf_in, **kwargs):
self.pdf_in = pdf_in
self.ppf_in = ppf_in
super().__init__(**kwargs)
def _pdf(self, x, *args):
return self.pdf_in(x)
def _ppf(self, q, *args):
return self.ppf_in(q)
class DistCdfPpf(rv_continuous):
"""Generate distribution from cdf and ppf."""
def __init__(self, cdf_in, ppf_in, **kwargs):
self.cdf_in = cdf_in
self.ppf_in = ppf_in
super().__init__(**kwargs)
def _cdf(self, x, *args):
return self.cdf_in(x)
def _ppf(self, q, *args):
return self.ppf_in(q)
class DistPdfCdfPpf(rv_continuous):
"""Generate distribution from pdf, cdf and ppf."""
def __init__(self, pdf_in, cdf_in, ppf_in, **kwargs):
self.pdf_in = pdf_in
self.cdf_in = cdf_in
self.ppf_in = ppf_in
super().__init__(**kwargs)
def _pdf(self, x, *args):
return self.pdf_in(x)
def _cdf(self, x, *args):
return self.cdf_in(x)
def _ppf(self, q, *args):
return self.ppf_in(q)
if __name__ == "__main__": # pragma: no cover
import doctest
doctest.testmod()
