Source code for gemseo.uncertainty.distributions.scipy.log_normal

# Copyright 2021 IRT Saint Exupéry, https://www.irt-saintexupery.com
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License version 3 as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
# Contributors:
#    INITIAL AUTHORS - initial API and implementation and/or initial
#                           documentation
#        :author: Matthias De Lozzo
#    OTHER AUTHORS   - MACROSCOPIC CHANGES
"""The SciPy-based log-normal distribution."""

from __future__ import annotations

from numpy import exp

from gemseo.uncertainty.distributions._log_normal_utils import compute_mu_l_and_sigma_l
from gemseo.uncertainty.distributions.base_settings.log_normal_settings import _LOCATION
from gemseo.uncertainty.distributions.base_settings.log_normal_settings import _MU
from gemseo.uncertainty.distributions.base_settings.log_normal_settings import _SET_LOG
from gemseo.uncertainty.distributions.base_settings.log_normal_settings import _SIGMA
from gemseo.uncertainty.distributions.scipy.distribution import SPDistribution
from gemseo.uncertainty.distributions.scipy.log_normal_settings import (
    SPLogNormalDistribution_Settings,
)




class SPLogNormalDistribution(SPDistribution):
    """The SciPy-based log-normal distribution."""

    Settings = SPLogNormalDistribution_Settings

    def __init__(
        self,
        mu: float = _MU,
        sigma: float = _SIGMA,
        location: float = _LOCATION,
        set_log: bool = _SET_LOG,
        settings: SPLogNormalDistribution_Settings | None = None,
    ) -> None:
        """
        Args:
            mu: Either the mean of the log-normal random variable
                or that of its logarithm when ``set_log`` is ``True``.
            sigma: Either the standard deviation of the log-normal random variable
                or that of its logarithm when ``set_log`` is ``True``.
            location: The location of the log-normal random variable.
            set_log: Whether ``mu`` and ``sigma`` apply
                to the logarithm of the log-normal random variable.
                Otherwise,
                ``mu`` and ``sigma`` apply to the log-normal random variable directly.
        """  # noqa: D205,D212,D415
        if settings is None:
            settings = SPLogNormalDistribution_Settings(
                mu=mu, sigma=sigma, location=location, set_log=set_log
            )

        if settings.set_log:
            log_mu, log_sigma = settings.mu, settings.sigma
        else:
            log_mu, log_sigma = compute_mu_l_and_sigma_l(
                settings.mu, settings.sigma, settings.location
            )

        super().__init__(
            interfaced_distribution="lognorm",
            parameters={
                "s": log_sigma,
                "loc": settings.location,
                "scale": exp(log_mu),
            },
            standard_parameters={
                self._MU: settings.mu,
                self._SIGMA: settings.sigma,
                self._LOC: settings.location,
            },
        )