Source code for gemseo.mlearning.transform.dimension_reduction.kpca
# -*- 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: Syver Doving Agdestein
# OTHER AUTHORS - MACROSCOPIC CHANGES
"""
Kernel Principal Component Analysis
===================================
The :class:`KPCA` class implements the KCPA wraps the KPCA from Scikit-learn.
Dependence
----------
This dimension reduction algorithm relies on the PCA class
of the `scikit-learn library <https://scikit-learn.org/stable/modules/
generated/sklearn.decomposition.PCA.html>`_.
"""
from __future__ import absolute_import, division, unicode_literals
from future import standard_library
from sklearn.decomposition import KernelPCA
from gemseo.mlearning.transform.dimension_reduction.dimension_reduction import (
DimensionReduction,
)
standard_library.install_aliases()
[docs]class KPCA(DimensionReduction):
""" Kernel principal component dimension reduction algorithm. """
def __init__(
self,
name="KPCA",
n_components=5,
fit_inverse_transform=True,
kernel="linear",
**parameters
):
"""Constructor.
:param str name: transformer name. Default: 'KPCA'.
:param int n_components: number of components. Default: 5.
:param bool fit_inverse_transform: Learn the inverse transform for
non-precomputed kernels. Default: True.
:param str kernel: kernel name ('linear', 'poly', 'rbf',
'sigmoid', 'cosine' or 'precomputed'). Default: 'linear'.
:param parameters: Optional parameters for sklearn KPCA constructor.
"""
super(KPCA, self).__init__(name, n_components=n_components, **parameters)
self.algo = KernelPCA(
n_components,
fit_inverse_transform=fit_inverse_transform,
kernel=kernel,
**parameters
)
[docs] def fit(self, data):
"""Fit transformer to data.
:param ndarray data: data to be fitted.
"""
self.algo.fit(data)