/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.math.linear; /** * An interface to classes that implement an algorithm to calculate the * QR-decomposition of a real matrix. *
This interface is based on the class with similar name from the * JAMA library, with the * following changes:
*solve
and isFullRank
methods have been replaced
* by a {@link #getSolver() getSolver} method and the equivalent methods provided by
* the returned {@link DecompositionSolver}.R is an upper-triangular matrix
* @return the R matrix */ RealMatrix getR(); /** * Returns the matrix Q of the decomposition. *Q is an orthogonal matrix
* @return the Q matrix */ RealMatrix getQ(); /** * Returns the transpose of the matrix Q of the decomposition. *Q is an orthogonal matrix
* @return the Q matrix */ RealMatrix getQT(); /** * Returns the Householder reflector vectors. *H is a lower trapezoidal matrix whose columns represent * each successive Householder reflector vector. This matrix is used * to compute Q.
* @return a matrix containing the Householder reflector vectors */ RealMatrix getH(); /** * Get a solver for finding the A × X = B solution in least square sense. * @return a solver */ DecompositionSolver getSolver(); }