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

# -*- coding: utf-8 -*-
# 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

"""Class to create a triangular distribution from the SciPy library.

This class inherits from :class:`.SPDistribution`.
"""

from __future__ import division, unicode_literals

from gemseo.uncertainty.distributions.scipy.distribution import SPDistribution


class SPTriangularDistribution(SPDistribution):
    """Create a triangular distribution.

    Example:
        >>> from gemseo.uncertainty.distributions.scipy.triangular import (
        ...     SPTriangularDistribution
        ... )
        >>> distribution = SPTriangularDistribution('x', -1, 0, 1)
        >>> print(distribution)
        triang(lower=-1, mode=0, upper=1)
    """

    def __init__(
        self,
        variable,  # type: str
        minimum=0.0,  # type: float
        mode=0.5,  # type: float
        maximum=1.0,  # type: float
        dimension=1,  # type: int
    ):  # noqa: D205,D212,D415
        # type: (...) -> None
        """
        Args:
            variable: The name of the triangular random variable.
            minimum: The minimum of the triangular random variable.
            mode: The mode of the triangular random variable.
            maximum: The maximum of the triangular random variable.
            dimension: The dimension of the triangular random variable.
        """
        parameters = {
            "loc": minimum,
            "scale": maximum - minimum,
            "c": (mode - minimum) / float(maximum - minimum),
        }
        standard_parameters = {
            self._LOWER: minimum,
            self._MODE: mode,
            self._UPPER: maximum,
        }
        super(SPTriangularDistribution, self).__init__(
            variable, "triang", parameters, dimension, standard_parameters
        )