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A fast and easy to use dense and sparse matrix linear algebra library written in Java.
/*
* Copyright (c) 2020, 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;
import javax.annotation.Generated;
import org.ejml.data.CMatrixD1;
import org.ejml.data.CMatrixRMaj;
import java.util.Random;
/**
* Contains a list of functions for creating random row complex matrices and vectors with different structures.
*
* @author Peter Abeles
*/
@Generated("org.ejml.dense.row.RandomMatrices_ZDRM")
public class RandomMatrices_CDRM {
/**
*
* Returns a matrix where all the elements are selected independently from
* a uniform distribution between -1 and 1 inclusive.
*
*
* @param numRow Number of rows in the new matrix.
* @param numCol Number of columns in the new matrix.
* @param rand Random number generator used to fill the matrix.
* @return The randomly generated matrix.
*/
public static CMatrixRMaj rectangle( int numRow, int numCol, Random rand ) {
return rectangle(numRow, numCol, -1, 1, rand);
}
/**
*
* Returns a matrix where all the elements are selected independently from
* a uniform distribution between 'min' and 'max' inclusive.
*
*
* @param numRow Number of rows in the new matrix.
* @param numCol Number of columns in the new matrix.
* @param min The minimum value each element can be.
* @param max The maximum value each element can be.
* @param rand Random number generator used to fill the matrix.
* @return The randomly generated matrix.
*/
public static CMatrixRMaj rectangle( int numRow, int numCol, float min, float max, Random rand ) {
CMatrixRMaj mat = new CMatrixRMaj(numRow, numCol);
fillUniform(mat, min, max, rand);
return mat;
}
/**
*
* Sets each element in the matrix to a value drawn from an uniform distribution from 0 to 1 inclusive.
*
*
* @param mat The matrix who is to be randomized. Modified.
* @param rand Random number generator used to fill the matrix.
*/
public static void fillUniform( CMatrixRMaj mat, Random rand ) {
fillUniform(mat, 0, 1, rand);
}
/**
*
* Sets each element in the matrix to a value drawn from an uniform distribution from 'min' to 'max' inclusive.
*
*
* @param min The minimum value each element can be.
* @param max The maximum value each element can be.
* @param mat The matrix who is to be randomized. Modified.
* @param rand Random number generator used to fill the matrix.
*/
public static void fillUniform( CMatrixD1 mat, float min, float max, Random rand ) {
float d[] = mat.getData();
int size = mat.getDataLength();
float r = max - min;
for (int i = 0; i < size; i++) {
d[i] = r*rand.nextFloat() + min;
}
}
/**
* Creates a random symmetric positive definite matrix.
*
* @param width The width of the square matrix it returns.
* @param rand Random number generator used to make the matrix.
* @return The random symmetric positive definite matrix.
*/
public static CMatrixRMaj hermitianPosDef( int width, Random rand ) {
// This is not formally proven to work. It just seems to work.
CMatrixRMaj a = RandomMatrices_CDRM.rectangle(width, 1, rand);
CMatrixRMaj b = new CMatrixRMaj(1, width);
CMatrixRMaj c = new CMatrixRMaj(width, width);
CommonOps_CDRM.transposeConjugate(a, b);
CommonOps_CDRM.mult(a, b, c);
for (int i = 0; i < width; i++) {
c.data[2*(i*width + i)] += 1;
}
return c;
}
/**
* Creates a random Hermitian matrix with elements from min to max value.
*
* @param length Width and height of the matrix.
* @param min Minimum value an element can have.
* @param max Maximum value an element can have.
* @param rand Random number generator.
* @return A symmetric matrix.
*/
public static CMatrixRMaj hermitian( int length, float min, float max, Random rand ) {
CMatrixRMaj A = new CMatrixRMaj(length, length);
fillHermitian(A, min, max, rand);
return A;
}
/**
* Assigns the provided square matrix to be a random Hermitian matrix with elements from min to max value.
*
* @param A The matrix that is to be modified. Must be square. Modified.
* @param min Minimum value an element can have.
* @param max Maximum value an element can have.
* @param rand Random number generator.
*/
public static void fillHermitian( CMatrixRMaj A, float min, float max, Random rand ) {
if (A.numRows != A.numCols)
throw new IllegalArgumentException("A must be a square matrix");
float range = max - min;
int length = A.numRows;
for (int i = 0; i < length; i++) {
A.set(i, i, rand.nextFloat()*range + min, 0);
for (int j = i + 1; j < length; j++) {
float real = rand.nextFloat()*range + min;
float imaginary = rand.nextFloat()*range + min;
A.set(i, j, real, imaginary);
A.set(j, i, real, -imaginary);
}
}
}
// /**
// * Creates an upper triangular matrix whose values are selected from a uniform distribution. If hessenberg
// * is greater than zero then a hessenberg matrix of the specified degree is created instead.
// *
// * @param dimen Number of rows and columns in the matrix..
// * @param hessenberg 0 for triangular matrix and > 0 for hessenberg matrix.
// * @param min minimum value an element can be.
// * @param max maximum value an element can be.
// * @param rand random number generator used.
// * @return The randomly generated matrix.
// */
// public static CMatrixRMaj createUpperTriangle( int dimen , int hessenberg , float min , float max , Random rand )
// {
// if( hessenberg < 0 )
// throw new RuntimeException("hessenberg must be more than or equal to 0");
//
// float range = max-min;
//
// CMatrixRMaj A = new CMatrixRMaj(dimen,dimen);
//
// for( int i = 0; i < dimen; i++ ) {
// int start = i <= hessenberg ? 0 : i-hessenberg;
//
// for( int j = start; j < dimen; j++ ) {
// float real = rand.nextFloat()*range + min;
// float imaginary = rand.nextFloat()*range + min;
//
// A.set(i,j, real, imaginary);
// }
//
// }
//
// return A;
// }
}