org.ejml.dense.row.decompose.UtilDecompositons_CDRM Maven / Gradle / Ivy
/*
* Copyright (c) 2009-2017, Peter Abeles. All Rights Reserved.
*
* This file is part of Efficient Java Matrix Library (EJML).
*
* Licensed 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.ejml.dense.row.decompose;
import org.ejml.data.CMatrixRMaj;
import org.ejml.dense.row.CommonOps_CDRM;
/**
* Helper functions for generic decompsotions.
*
* @author Peter Abeles
*/
public class UtilDecompositons_CDRM {
public static CMatrixRMaj checkIdentity(CMatrixRMaj A, int numRows, int numCols) {
if( A == null ) {
return CommonOps_CDRM.identity(numRows,numCols);
} else if( numRows != A.numRows || numCols != A.numCols )
throw new IllegalArgumentException("Input is not "+numRows+" x "+numCols+" matrix");
else
CommonOps_CDRM.setIdentity(A);
return A;
}
public static CMatrixRMaj checkZeros(CMatrixRMaj A , int numRows , int numCols) {
if( A == null ) {
return new CMatrixRMaj(numRows,numCols);
} else if( numRows != A.numRows || numCols != A.numCols )
throw new IllegalArgumentException("Input is not "+numRows+" x "+numCols+" matrix");
else
A.zero();
return A;
}
/**
* Creates a zeros matrix only if A does not already exist. If it does exist it will fill
* the lower triangular portion with zeros.
*/
public static CMatrixRMaj checkZerosLT(CMatrixRMaj A , int numRows , int numCols) {
if( A == null ) {
return new CMatrixRMaj(numRows,numCols);
} else if( numRows != A.numRows || numCols != A.numCols )
throw new IllegalArgumentException("Input is not "+numRows+" x "+numCols+" matrix");
else {
for( int i = 0; i < A.numRows; i++ ) {
int index = i*A.numCols*2;
int end = index + Math.min(i,A.numCols)*2;;
while( index < end ) {
A.data[index++] = 0;
}
}
}
return A;
}
/**
* Creates a zeros matrix only if A does not already exist. If it does exist it will fill
* the upper triangular portion with zeros.
*/
public static CMatrixRMaj checkZerosUT(CMatrixRMaj A , int numRows , int numCols) {
if( A == null ) {
return new CMatrixRMaj(numRows,numCols);
} else if( numRows != A.numRows || numCols != A.numCols )
throw new IllegalArgumentException("Input is not "+numRows+" x "+numCols+" matrix");
else {
int maxRows = Math.min(A.numRows,A.numCols);
for( int i = 0; i < maxRows; i++ ) {
int index = (i*A.numCols + i+1)*2;
int end = (i*A.numCols + A.numCols)*2;
while( index < end ) {
A.data[index++] = 0;
}
}
}
return A;
}
}