org.ejml.sparse.csc.MatrixFeatures_FSCC Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of ejml-fsparse Show documentation
Show all versions of ejml-fsparse Show documentation
A fast and easy to use dense and sparse matrix linear algebra library written in Java.
The newest version!
/*
* Copyright (c) 2022, 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.sparse.csc;
import javax.annotation.Generated;
import org.ejml.UtilEjml;
import org.ejml.data.FGrowArray;
import org.ejml.data.FMatrixSparseCSC;
import org.ejml.data.IGrowArray;
import org.ejml.interfaces.decomposition.CholeskySparseDecomposition;
import org.ejml.sparse.csc.decomposition.chol.CholeskyUpLooking_FSCC;
/**
* Functions for computing the features/properties of matrices.
*
* @author Peter Abeles
*/
@Generated("org.ejml.sparse.csc.MatrixFeatures_DSCC")
public class MatrixFeatures_FSCC {
private MatrixFeatures_FSCC(){}
public static boolean isEquals(FMatrixSparseCSC a , FMatrixSparseCSC b ) {
if( !a.indicesSorted || !b.indicesSorted )
throw new IllegalArgumentException("Inputs must have sorted indices");
if( !isSameStructure(a,b) )
return false;
for (int i = 0; i < a.nz_length; i++) {
if( a.nz_values[i] != b.nz_values[i] )
return false;
}
return true;
}
public static boolean isEquals(FMatrixSparseCSC a , FMatrixSparseCSC b , float tol ) {
if( !a.indicesSorted || !b.indicesSorted )
throw new IllegalArgumentException("Inputs must have sorted indices");
if( !isSameStructure(a,b) )
return false;
for (int i = 0; i < a.nz_length; i++) {
if( Math.abs(a.nz_values[i]-b.nz_values[i]) > tol )
return false;
}
return true;
}
public static boolean isEqualsSort(FMatrixSparseCSC a , FMatrixSparseCSC b , float tol ) {
if( !a.indicesSorted )
a.sortIndices(null);
if( !b.indicesSorted )
b.sortIndices(null);
if( !isSameStructure(a,b) )
return false;
for (int i = 0; i < a.nz_length; i++) {
if( Math.abs(a.nz_values[i]-b.nz_values[i]) > tol )
return false;
}
return true;
}
public static boolean isIdenticalSort(FMatrixSparseCSC a , FMatrixSparseCSC b , float tol ) {
if( !a.indicesSorted )
a.sortIndices(null);
if( !b.indicesSorted )
b.sortIndices(null);
if( !isSameStructure(a,b) )
return false;
for (int i = 0; i < a.nz_length; i++) {
if( !UtilEjml.isIdentical(a.nz_values[i],b.nz_values[i], tol))
return false;
}
return true;
}
/**
* Checks to see if the two matrices have the same shape and same pattern of non-zero elements
*
* @param a Matrix
* @param b Matrix
* @return true if the structure is the same
*/
public static boolean isSameStructure(FMatrixSparseCSC a , FMatrixSparseCSC b) {
if( a.numRows == b.numRows && a.numCols == b.numCols && a.nz_length == b.nz_length) {
for (int i = 0; i <= a.numCols; i++) {
if( a.col_idx[i] != b.col_idx[i] )
return false;
}
for (int i = 0; i < a.nz_length; i++) {
if( a.nz_rows[i] != b.nz_rows[i] )
return false;
}
return true;
}
return false;
}
public static boolean hasUncountable( FMatrixSparseCSC A ) {
for(int i = 0; i < A.nz_length; i++ ) {
if(UtilEjml.isUncountable(A.nz_values[i])) {
return true;
}
}
return false;
}
public static boolean isZeros(FMatrixSparseCSC A , float tol ) {
for(int i = 0; i < A.nz_length; i++ ) {
if(Math.abs(A.nz_values[i]) > tol) {
return false;
}
}
return true;
}
public static boolean isIdentity(FMatrixSparseCSC A , float tol ) {
if( A.numCols != A.numRows )
return false;
if( A.nz_length != A.numCols )
return false;
for( int i = 1; i <= A.numCols; i++ ) {
if( A.col_idx[i] != i)
return false;
if( Math.abs(A.nz_values[i-1]-1) > tol )
return false;
}
return true;
}
/**
*
* Checks to see if a matrix is lower triangular or Hessenberg. A Hessenberg matrix of degree N
* has the following property:
*
* aij ≤ 0 for all i < j+N
*
* A triangular matrix is a Hessenberg matrix of degree 0. Only the upper most diagonal elements are
* explicitly checked to see if they are non-zero
*
* @param A Matrix being tested. Not modified.
* @param hessenberg The degree of being hessenberg.
* @param tol How not zero diagonal elements must be.
* @return If it is an upper triangular/hessenberg matrix or not.
*/
public static boolean isLowerTriangle(FMatrixSparseCSC A , int hessenberg , float tol )
{
if( A.numCols != A.numRows )
return false;
// diagonal elements must be non-zero
if( A.nz_length < A.numCols-hessenberg )
return false;
for (int col = 0; col < A.numCols; col++) {
int idx0 = A.col_idx[col];
int idx1 = A.col_idx[col+1];
// at least one element in each column
if( col >= hessenberg ) {
if (idx0 == idx1)
return false;
// first element must be (i,i)
if (A.nz_rows[idx0] != Math.max(0, col - hessenberg))
return false;
}
// diagonal elements must not be zero
if( col-hessenberg >= 0 && Math.abs(A.nz_values[idx0]) <= tol )
return false;
}
return true;
}
public static boolean isTranspose( FMatrixSparseCSC A , FMatrixSparseCSC B , float tol ) {
if( A.numCols != B.numRows || A.numRows != B.numCols )
return false;
if( A.nz_length != B.nz_length )
return false;
if( !A.indicesSorted )
throw new IllegalArgumentException("A must have sorted indicies");
FMatrixSparseCSC Btran = new FMatrixSparseCSC(B.numCols,B.numRows,B.nz_length);
CommonOps_FSCC.transpose(B,Btran,null);
Btran.sortIndices(null);
for (int i = 0; i < B.nz_length; i++) {
if( A.nz_rows[i] != Btran.nz_rows[i] )
return false;
if( Math.abs(A.nz_values[i] - Btran.nz_values[i]) > tol )
return false;
}
return true;
}
/**
* Returns true if the input is a vector
* @param a A matrix or vector
* @return true if it's a vector. Column or row.
*/
public static boolean isVector(FMatrixSparseCSC a) {
return (a.numCols == 1 && a.numRows > 1) || (a.numRows == 1 && a.numCols>1);
}
/**
* Checks to see if the matrix is symmetric to within tolerance.
*
* @param A Matrix being tested. Not modified.
* @param tol Tolerance that defines how similar two values must be to be considered identical
* @return true if symmetric or false if not
*/
public static boolean isSymmetric( FMatrixSparseCSC A , float tol ) {
if( A.numRows != A.numCols )
return false;
int N = A.numCols;
for (int i = 0; i < N; i++) {
int idx0 = A.col_idx[i];
int idx1 = A.col_idx[i+1];
for (int index = idx0; index < idx1; index++) {
int j = A.nz_rows[index];
float value_ji = A.nz_values[index];
float value_ij = A.get(i,j);
if( Math.abs(value_ij-value_ji) > tol )
return false;
}
}
return true;
}
/**
*
* Checks to see if the matrix is positive definite.
*
*
* xT A x > 0
* for all x where x is a non-zero vector and A is a symmetric matrix.
*
*
* @param A square symmetric matrix. Not modified.
*
* @return True if it is positive definite and false if it is not.
*/
public static boolean isPositiveDefinite( FMatrixSparseCSC A ) {
if( A.numRows != A.numCols )
return false;
CholeskySparseDecomposition chol = new CholeskyUpLooking_FSCC();
return chol.decompose(A);
}
/**
*
* Checks to see if a matrix is orthogonal or isometric.
*
*
* @param Q The matrix being tested. Not modified.
* @param tol Tolerance.
* @return True if it passes the test.
*/
public static boolean isOrthogonal(FMatrixSparseCSC Q , float tol )
{
if( Q.numRows < Q.numCols ) {
throw new IllegalArgumentException("The number of rows must be more than or equal to the number of columns");
}
IGrowArray gw=new IGrowArray();
FGrowArray gx=new FGrowArray();
for( int i = 0; i < Q.numRows; i++ ) {
for( int j = i+1; j < Q.numCols; j++ ) {
float val = CommonOps_FSCC.dotInnerColumns(Q,i,Q,j,gw,gx);
if( !(Math.abs(val) <= tol))
return false;
}
}
return true;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy