org.ejml.dense.fixed.CommonOps_DDF2 Maven / Gradle / Ivy
/*
* Copyright (c) 2009-2020, 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.fixed;
import org.ejml.UtilEjml;
import org.ejml.data.DMatrix2;
import org.ejml.data.DMatrix2x2;
/**
* Common matrix operations for fixed sized matrices which are 2 x 2 or 2 element vectors.
* DO NOT MODIFY. Automatically generated code created by GenerateCommonOps_DDF
*
* @author Peter Abeles
*/
public class CommonOps_DDF2 {
/**
* Performs the following operation:
*
* c = a + b
* cij = aij + bij
*
*
*
* Matrix C can be the same instance as Matrix A and/or B.
*
*
* @param a A Matrix. Not modified.
* @param b A Matrix. Not modified.
* @param c A Matrix where the results are stored. Modified.
*/
public static void add( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c ) {
c.a11 = a.a11 + b.a11;
c.a12 = a.a12 + b.a12;
c.a21 = a.a21 + b.a21;
c.a22 = a.a22 + b.a22;
}
/**
* Performs the following operation:
*
* c = a + b
* ci = ai + bi
*
*
*
* Vector C can be the same instance as Vector A and/or B.
*
*
* @param a A Vector. Not modified.
* @param b A Vector. Not modified.
* @param c A Vector where the results are stored. Modified.
*/
public static void add( DMatrix2 a , DMatrix2 b , DMatrix2 c ) {
c.a1 = a.a1 + b.a1;
c.a2 = a.a2 + b.a2;
}
/**
* Performs the following operation:
*
* a = a + b
* aij = aij + bij
*
*
* @param a A Matrix. Modified.
* @param b A Matrix. Not modified.
*/
public static void addEquals( DMatrix2x2 a , DMatrix2x2 b ) {
a.a11 += b.a11;
a.a12 += b.a12;
a.a21 += b.a21;
a.a22 += b.a22;
}
/**
* Performs the following operation:
*
* a = a + b
* ai = ai + bi
*
*
* @param a A Vector. Modified.
* @param b A Vector. Not modified.
*/
public static void addEquals( DMatrix2 a , DMatrix2 b ) {
a.a1 += b.a1;
a.a2 += b.a2;
}
/**
* Performs the following operation:
*
* c = a - b
* cij = aij - bij
*
*
*
* Matrix C can be the same instance as Matrix A and/or B.
*
*
* @param a A Matrix. Not modified.
* @param b A Matrix. Not modified.
* @param c A Matrix where the results are stored. Modified.
*/
public static void subtract( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c ) {
c.a11 = a.a11 - b.a11;
c.a12 = a.a12 - b.a12;
c.a21 = a.a21 - b.a21;
c.a22 = a.a22 - b.a22;
}
/**
* Performs the following operation:
*
* c = a - b
* ci = ai - bi
*
*
*
* Vector C can be the same instance as Vector A and/or B.
*
*
* @param a A Vector. Not modified.
* @param b A Vector. Not modified.
* @param c A Vector where the results are stored. Modified.
*/
public static void subtract( DMatrix2 a , DMatrix2 b , DMatrix2 c ) {
c.a1 = a.a1 - b.a1;
c.a2 = a.a2 - b.a2;
}
/**
* Performs the following operation:
*
* a = a - b
* aij = aij - bij
*
*
* @param a A Matrix. Modified.
* @param b A Matrix. Not modified.
*/
public static void subtractEquals( DMatrix2x2 a , DMatrix2x2 b ) {
a.a11 -= b.a11;
a.a12 -= b.a12;
a.a21 -= b.a21;
a.a22 -= b.a22;
}
/**
* Performs the following operation:
*
* a = a - b
* ai = ai - bi
*
*
* @param a A Vector. Modified.
* @param b A Vector. Not modified.
*/
public static void subtractEquals( DMatrix2 a , DMatrix2 b ) {
a.a1 -= b.a1;
a.a2 -= b.a2;
}
/**
* Performs an in-place transpose. This algorithm is only efficient for square
* matrices.
*
* @param m The matrix that is to be transposed. Modified.
*/
public static void transpose( DMatrix2x2 m ) {
double tmp;
tmp = m.a12; m.a12 = m.a21; m.a21 = tmp;
}
/**
*
* Transposes matrix 'a' and stores the results in 'b':
*
* bij = aji
* where 'b' is the transpose of 'a'.
*
*
* @param input The original matrix. Not modified.
* @param output Where the transpose is stored. If null a new matrix is created. Modified.
* @return The transposed matrix.
*/
public static DMatrix2x2 transpose( DMatrix2x2 input , DMatrix2x2 output ) {
if( input == null )
input = new DMatrix2x2();
UtilEjml.checkSameInstance(input,output);
output.a11 = input.a11;
output.a12 = input.a21;
output.a21 = input.a12;
output.a22 = input.a22;
return output;
}
/**
* Performs the following operation:
*
* c = a * b
*
* cij = ∑k=1:n { aik * bkj}
*
*
* @param a The left matrix in the multiplication operation. Not modified.
* @param b The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void mult( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = a.a11*b.a11 + a.a12*b.a21;
c.a12 = a.a11*b.a12 + a.a12*b.a22;
c.a21 = a.a21*b.a11 + a.a22*b.a21;
c.a22 = a.a21*b.a12 + a.a22*b.a22;
}
/**
* Performs the following operation:
*
* c = α * a * b
*
* cij = α ∑k=1:n { aik * bkj}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void mult( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = alpha*(a.a11*b.a11 + a.a12*b.a21);
c.a12 = alpha*(a.a11*b.a12 + a.a12*b.a22);
c.a21 = alpha*(a.a21*b.a11 + a.a22*b.a21);
c.a22 = alpha*(a.a21*b.a12 + a.a22*b.a22);
}
/**
* Performs the following operation:
*
* c = aT * b
*
* cij = ∑k=1:n { aki * bkj}
*
*
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multTransA( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = a.a11*b.a11 + a.a21*b.a21;
c.a12 = a.a11*b.a12 + a.a21*b.a22;
c.a21 = a.a12*b.a11 + a.a22*b.a21;
c.a22 = a.a12*b.a12 + a.a22*b.a22;
}
/**
* Performs the following operation:
*
* c = α * aT * b
*
* cij = α * ∑k=1:n { aki * bkj}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multTransA( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = alpha*(a.a11*b.a11 + a.a21*b.a21);
c.a12 = alpha*(a.a11*b.a12 + a.a21*b.a22);
c.a21 = alpha*(a.a12*b.a11 + a.a22*b.a21);
c.a22 = alpha*(a.a12*b.a12 + a.a22*b.a22);
}
/**
*
* Performs the following operation:
*
* c = aT * bT
* cij = ∑k=1:n { aki * bjk}
*
*
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multTransAB( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = a.a11*b.a11 + a.a21*b.a12;
c.a12 = a.a11*b.a21 + a.a21*b.a22;
c.a21 = a.a12*b.a11 + a.a22*b.a12;
c.a22 = a.a12*b.a21 + a.a22*b.a22;
}
/**
*
* Performs the following operation:
*
* c = α*aT * bT
* cij = α*∑k=1:n { aki * bjk}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multTransAB( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = alpha*(a.a11*b.a11 + a.a21*b.a12);
c.a12 = alpha*(a.a11*b.a21 + a.a21*b.a22);
c.a21 = alpha*(a.a12*b.a11 + a.a22*b.a12);
c.a22 = alpha*(a.a12*b.a21 + a.a22*b.a22);
}
/**
*
* Performs the following operation:
*
* c = a * bT
* cij = ∑k=1:n { aik * bjk}
*
*
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multTransB( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = a.a11*b.a11 + a.a12*b.a12;
c.a12 = a.a11*b.a21 + a.a12*b.a22;
c.a21 = a.a21*b.a11 + a.a22*b.a12;
c.a22 = a.a21*b.a21 + a.a22*b.a22;
}
/**
*
* Performs the following operation:
*
* c = α * a * bT
* cij = α*∑k=1:n { aik * bjk}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multTransB( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 = alpha*(a.a11*b.a11 + a.a12*b.a12);
c.a12 = alpha*(a.a11*b.a21 + a.a12*b.a22);
c.a21 = alpha*(a.a21*b.a11 + a.a22*b.a12);
c.a22 = alpha*(a.a21*b.a21 + a.a22*b.a22);
}
/**
* Performs the following operation:
*
* c += a * b
*
* cij += ∑k=1:n { aik * bkj}
*
*
* @param a The left matrix in the multiplication operation. Not modified.
* @param b The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAdd( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += a.a11*b.a11 + a.a12*b.a21;
c.a12 += a.a11*b.a12 + a.a12*b.a22;
c.a21 += a.a21*b.a11 + a.a22*b.a21;
c.a22 += a.a21*b.a12 + a.a22*b.a22;
}
/**
* Performs the following operation:
*
* c += α * a * b
*
* cij += α ∑k=1:n { aik * bkj}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAdd( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += alpha*(a.a11*b.a11 + a.a12*b.a21);
c.a12 += alpha*(a.a11*b.a12 + a.a12*b.a22);
c.a21 += alpha*(a.a21*b.a11 + a.a22*b.a21);
c.a22 += alpha*(a.a21*b.a12 + a.a22*b.a22);
}
/**
* Performs the following operation:
*
* c += aT * b
*
* cij += ∑k=1:n { aki * bkj}
*
*
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAddTransA( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += a.a11*b.a11 + a.a21*b.a21;
c.a12 += a.a11*b.a12 + a.a21*b.a22;
c.a21 += a.a12*b.a11 + a.a22*b.a21;
c.a22 += a.a12*b.a12 + a.a22*b.a22;
}
/**
* Performs the following operation:
*
* c += α * aT * b
*
* cij += α * ∑k=1:n { aki * bkj}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAddTransA( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += alpha*(a.a11*b.a11 + a.a21*b.a21);
c.a12 += alpha*(a.a11*b.a12 + a.a21*b.a22);
c.a21 += alpha*(a.a12*b.a11 + a.a22*b.a21);
c.a22 += alpha*(a.a12*b.a12 + a.a22*b.a22);
}
/**
*
* Performs the following operation:
*
* c += aT * bT
* cij += ∑k=1:n { aki * bjk}
*
*
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAddTransAB( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += a.a11*b.a11 + a.a21*b.a12;
c.a12 += a.a11*b.a21 + a.a21*b.a22;
c.a21 += a.a12*b.a11 + a.a22*b.a12;
c.a22 += a.a12*b.a21 + a.a22*b.a22;
}
/**
*
* Performs the following operation:
*
* c += α*aT * bT
* cij += α*∑k=1:n { aki * bjk}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAddTransAB( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += alpha*(a.a11*b.a11 + a.a21*b.a12);
c.a12 += alpha*(a.a11*b.a21 + a.a21*b.a22);
c.a21 += alpha*(a.a12*b.a11 + a.a22*b.a12);
c.a22 += alpha*(a.a12*b.a21 + a.a22*b.a22);
}
/**
*
* Performs the following operation:
*
* c += a * bT
* cij += ∑k=1:n { aik * bjk}
*
*
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAddTransB( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += a.a11*b.a11 + a.a12*b.a12;
c.a12 += a.a11*b.a21 + a.a12*b.a22;
c.a21 += a.a21*b.a11 + a.a22*b.a12;
c.a22 += a.a21*b.a21 + a.a22*b.a22;
}
/**
*
* Performs the following operation:
*
* c += α * a * bT
* cij += α*∑k=1:n { aik * bjk}
*
*
* @param alpha Scaling factor.
* @param a (Input) The left matrix in the multiplication operation. Not modified.
* @param b (Input) The right matrix in the multiplication operation. Not modified.
* @param c (Output) Where the results of the operation are stored. Modified.
*/
public static void multAddTransB( double alpha , DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c) {
UtilEjml.checkSameInstance(a,c);
UtilEjml.checkSameInstance(b,c);
c.a11 += alpha*(a.a11*b.a11 + a.a12*b.a12);
c.a12 += alpha*(a.a11*b.a21 + a.a12*b.a22);
c.a21 += alpha*(a.a21*b.a11 + a.a22*b.a12);
c.a22 += alpha*(a.a21*b.a21 + a.a22*b.a22);
}
/**
* C = αA + βu*vT
*
* @param alpha scale factor applied to A
* @param A matrix
* @param beta scale factor applies to outer product
* @param u vector
* @param v vector
* @param C Storage for solution. Can be same instance as A.
*/
public static void multAddOuter( double alpha , DMatrix2x2 A , double beta , DMatrix2 u , DMatrix2 v , DMatrix2x2 C ) {
C.a11 = alpha*A.a11 + beta*u.a1*v.a1;
C.a12 = alpha*A.a12 + beta*u.a1*v.a2;
C.a21 = alpha*A.a21 + beta*u.a2*v.a1;
C.a22 = alpha*A.a22 + beta*u.a2*v.a2;
}
/**
* Performs matrix to vector multiplication:
*
* c = a * b
*
* ci = ∑k=1:n { aik * bk}
*
*
* @param a The left matrix in the multiplication operation. Not modified.
* @param b The right vector in the multiplication operation. Not modified.
* @param c Where the results of the operation are stored. Modified.
*/
public static void mult( DMatrix2x2 a , DMatrix2 b , DMatrix2 c) {
c.a1 = a.a11*b.a1 + a.a12*b.a2;
c.a2 = a.a21*b.a1 + a.a22*b.a2;
}
/**
* Performs vector to matrix multiplication:
*
* c = a * b
*
* cj = ∑k=1:n { bk * akj }
*
*
* @param a The left vector in the multiplication operation. Not modified.
* @param b The right matrix in the multiplication operation. Not modified.
* @param c Where the results of the operation are stored. Modified.
*/
public static void mult( DMatrix2 a , DMatrix2x2 b , DMatrix2 c) {
c.a1 = a.a1*b.a11 + a.a2*b.a21;
c.a2 = a.a1*b.a12 + a.a2*b.a22;
}
/**
* Performs the vector dot product:
*
* c = a * b
*
* c ≥ ∑k=1:n { bk * ak }
*
*
* @param a The left vector in the multiplication operation. Not modified.
* @param b The right matrix in the multiplication operation. Not modified.
* @return The dot product
*/
public static double dot( DMatrix2 a , DMatrix2 b ) {
return a.a1*b.a1 + a.a2*b.a2;
}
/**
* Sets all the diagonal elements equal to one and everything else equal to zero.
* If this is a square matrix then it will be an identity matrix.
*
* @param a A matrix.
*/
public static void setIdentity( DMatrix2x2 a ) {
a.a11 = 1; a.a21 = 0;
a.a12 = 0; a.a22 = 1;
}
/**
* Inverts matrix 'a' using minor matrices and stores the results in 'inv'. Scaling is applied to improve
* stability against overflow and underflow.
*
* WARNING: Potentially less stable than using LU decomposition.
*
* @param a Input matrix. Not modified.
* @param inv Inverted output matrix. Modified.
* @return true if it was successful or false if it failed. Not always reliable.
*/
public static boolean invert( DMatrix2x2 a , DMatrix2x2 inv ) {
double scale = 1.0/elementMaxAbs(a);
double a11 = a.a11*scale;
double a12 = a.a12*scale;
double a21 = a.a21*scale;
double a22 = a.a22*scale;
double m11 = a22;
double m12 = -( a21);
double m21 = -( a12);
double m22 = a11;
double det = (a11*m11 + a12*m12)/scale;
inv.a11 = m11/det;
inv.a12 = m21/det;
inv.a21 = m12/det;
inv.a22 = m22/det;
return !Double.isNaN(det) && !Double.isInfinite(det);
}
/**
* Computes the determinant using minor matrices.
* WARNING: Potentially less stable than using LU decomposition.
*
* @param mat Input matrix. Not modified.
* @return The determinant.
*/
public static double det( DMatrix2x2 mat ) {
return mat.a11*mat.a22 - mat.a12*mat.a21;
}
/**
* Performs a lower Cholesky decomposition of matrix 'A' and stores result in A.
*
* @param A (Input) SPD Matrix. (Output) lower cholesky.
* @return true if it was successful or false if it failed. Not always reliable.
*/
public static boolean cholL( DMatrix2x2 A ) {
A.a11 = Math.sqrt(A.a11);
A.a12 = 0;
A.a21 = (A.a21)/A.a11;
A.a22 = Math.sqrt(A.a22-A.a21*A.a21);
return !UtilEjml.isUncountable(A.a22);
}
/**
* Performs an upper Cholesky decomposition of matrix 'A' and stores result in A.
*
* @param A (Input) SPD Matrix. (Output) upper cholesky.
* @return true if it was successful or false if it failed. Not always reliable.
*/
public static boolean cholU( DMatrix2x2 A ) {
A.a11 = Math.sqrt(A.a11);
A.a21 = 0;
A.a12 = (A.a12)/A.a11;
A.a22 = Math.sqrt(A.a22-A.a12*A.a12);
return !UtilEjml.isUncountable(A.a22);
}
/**
*
* This computes the trace of the matrix:
*
* trace = ∑i=1:n { aii }
*
*
* The trace is only defined for square matrices.
*
*
* @param a A square matrix. Not modified.
*/
public static double trace( DMatrix2x2 a ) {
return a.a11 + a.a22;
}
/**
*
* Extracts all diagonal elements from 'input' and places them inside the 'out' vector. Elements
* are in sequential order.
*
*
*
* @param input Matrix. Not modified.
* @param out Vector containing diagonal elements. Modified.
*/
public static void diag( DMatrix2x2 input , DMatrix2 out ) {
out.a1 = input.a11;
out.a2 = input.a22;
}
/**
*
* Returns the value of the element in the matrix that has the largest value.
*
* Max{ aij } for all i and j
*
*
* @param a A matrix. Not modified.
* @return The max element value of the matrix.
*/
public static double elementMax( DMatrix2x2 a ) {
double max = a.a11;
if( a.a12 > max ) max = a.a12;
if( a.a21 > max ) max = a.a21;
if( a.a22 > max ) max = a.a22;
return max;
}
/**
*
* Returns the value of the element in the vector that has the largest value.
*
* Max{ ai } for all i
*
*
* @param a A vector. Not modified.
* @return The max element value of the matrix.
*/
public static double elementMax( DMatrix2 a ) {
double max = a.a1;
if( a.a2 > max ) max = a.a2;
return max;
}
/**
*
* Returns the absolute value of the element in the matrix that has the largest absolute value.
*
* Max{ |aij| } for all i and j
*
*
* @param a A matrix. Not modified.
* @return The max abs element value of the matrix.
*/
public static double elementMaxAbs( DMatrix2x2 a ) {
double max = Math.abs(a.a11);
double tmp = Math.abs(a.a12); if( tmp > max ) max = tmp;
tmp = Math.abs(a.a21); if( tmp > max ) max = tmp;
tmp = Math.abs(a.a22); if( tmp > max ) max = tmp;
return max;
}
/**
*
* Returns the absolute value of the element in the vector that has the largest absolute value.
*
* Max{ |ai| } for all i
*
*
* @param a A matrix. Not modified.
* @return The max abs element value of the vector.
*/
public static double elementMaxAbs( DMatrix2 a ) {
double max = Math.abs(a.a1);
double tmp = Math.abs(a.a2); if( tmp > max ) max = tmp;
tmp = Math.abs(a.a2); if( tmp > max ) max = tmp;
return max;
}
/**
*
* Returns the value of the element in the matrix that has the minimum value.
*
* Min{ aij } for all i and j
*
*
* @param a A matrix. Not modified.
* @return The value of element in the matrix with the minimum value.
*/
public static double elementMin( DMatrix2x2 a ) {
double min = a.a11;
if( a.a12 < min ) min = a.a12;
if( a.a21 < min ) min = a.a21;
if( a.a22 < min ) min = a.a22;
return min;
}
/**
*
* Returns the value of the element in the vector that has the minimum value.
*
* Min{ ai } for all
*
*
* @param a A matrix. Not modified.
* @return The value of element in the vector with the minimum value.
*/
public static double elementMin( DMatrix2 a ) {
double min = a.a1;
if( a.a2 < min ) min = a.a2;
return min;
}
/**
*
* Returns the absolute value of the element in the matrix that has the smallest absolute value.
*
* Min{ |aij| } for all i and j
*
*
* @param a A matrix. Not modified.
* @return The max element value of the matrix.
*/
public static double elementMinAbs( DMatrix2x2 a ) {
double min = Math.abs(a.a11);
double tmp = Math.abs(a.a12); if( tmp < min ) min = tmp;
tmp = Math.abs(a.a21); if( tmp < min ) min = tmp;
tmp = Math.abs(a.a22); if( tmp < min ) min = tmp;
return min;
}
/**
*
* Returns the absolute value of the element in the vector that has the smallest absolute value.
*
* Min{ |ai| } for all i
*
*
* @param a A matrix. Not modified.
* @return The max element value of the vector.
*/
public static double elementMinAbs( DMatrix2 a ) {
double min = Math.abs(a.a1);
double tmp = Math.abs(a.a1); if( tmp < min ) min = tmp;
tmp = Math.abs(a.a2); if( tmp < min ) min = tmp;
return min;
}
/**
* Performs an element by element multiplication operation:
*
* aij = aij * bij
*
* @param a The left matrix in the multiplication operation. Modified.
* @param b The right matrix in the multiplication operation. Not modified.
*/
public static void elementMult( DMatrix2x2 a , DMatrix2x2 b) {
a.a11 *= b.a11; a.a12 *= b.a12;
a.a21 *= b.a21; a.a22 *= b.a22;
}
/**
* Performs an element by element multiplication operation:
*
* ai = ai * bi
*
* @param a The left vector in the multiplication operation. Modified.
* @param b The right vector in the multiplication operation. Not modified.
*/
public static void elementMult( DMatrix2 a , DMatrix2 b) {
a.a1 *= b.a1;
a.a2 *= b.a2;
}
/**
* Performs an element by element multiplication operation:
*
* cij = aij * bij
*
* @param a The left matrix in the multiplication operation. Not modified.
* @param b The right matrix in the multiplication operation. Not modified.
* @param c Where the results of the operation are stored. Modified.
*/
public static void elementMult( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c ) {
c.a11 = a.a11*b.a11; c.a12 = a.a12*b.a12;
c.a21 = a.a21*b.a21; c.a22 = a.a22*b.a22;
}
/**
* Performs an element by element multiplication operation:
*
* ci = ai * bj
*
* @param a The left vector in the multiplication operation. Not modified.
* @param b The right vector in the multiplication operation. Not modified.
* @param c Where the results of the operation are stored. Modified.
*/
public static void elementMult( DMatrix2 a , DMatrix2 b , DMatrix2 c ) {
c.a1 = a.a1*b.a1;
c.a2 = a.a2*b.a2;
}
/**
* Performs an element by element division operation:
*
* aij = aij / bij
*
* @param a The left matrix in the division operation. Modified.
* @param b The right matrix in the division operation. Not modified.
*/
public static void elementDiv( DMatrix2x2 a , DMatrix2x2 b) {
a.a11 /= b.a11; a.a12 /= b.a12;
a.a21 /= b.a21; a.a22 /= b.a22;
}
/**
* Performs an element by element division operation:
*
* ai = ai / bi
*
* @param a The left vector in the division operation. Modified.
* @param b The right vector in the division operation. Not modified.
*/
public static void elementDiv( DMatrix2 a , DMatrix2 b) {
a.a1 /= b.a1;
a.a2 /= b.a2;
}
/**
* Performs an element by element division operation:
*
* cij = aij / bij
*
* @param a The left matrix in the division operation. Not modified.
* @param b The right matrix in the division operation. Not modified.
* @param c Where the results of the operation are stored. Modified.
*/
public static void elementDiv( DMatrix2x2 a , DMatrix2x2 b , DMatrix2x2 c ) {
c.a11 = a.a11/b.a11; c.a12 = a.a12/b.a12;
c.a21 = a.a21/b.a21; c.a22 = a.a22/b.a22;
}
/**
* Performs an element by element division operation:
*
* ci = ai / bi
*
* @param a The left vector in the division operation. Not modified.
* @param b The right vector in the division operation. Not modified.
* @param c Where the results of the operation are stored. Modified.
*/
public static void elementDiv( DMatrix2 a , DMatrix2 b , DMatrix2 c ) {
c.a1 = a.a1/b.a1;
c.a2 = a.a2/b.a2;
}
/**
*
* Performs an in-place element by element scalar multiplication.
*
* aij = α*aij
*
*
* @param a The matrix that is to be scaled. Modified.
* @param alpha the amount each element is multiplied by.
*/
public static void scale( double alpha , DMatrix2x2 a ) {
a.a11 *= alpha; a.a12 *= alpha;
a.a21 *= alpha; a.a22 *= alpha;
}
/**
*
* Performs an in-place element by element scalar multiplication.
*
* aij = α*aij
*
*
* @param a The vector that is to be scaled. Modified.
* @param alpha the amount each element is multiplied by.
*/
public static void scale( double alpha , DMatrix2 a ) {
a.a1 *= alpha;
a.a2 *= alpha;
}
/**
*
* Performs an element by element scalar multiplication.
*
* bij = α*aij
*
*
* @param alpha the amount each element is multiplied by.
* @param a The matrix that is to be scaled. Not modified.
* @param b Where the scaled matrix is stored. Modified.
*/
public static void scale( double alpha , DMatrix2x2 a , DMatrix2x2 b ) {
b.a11 = a.a11*alpha; b.a12 = a.a12*alpha;
b.a21 = a.a21*alpha; b.a22 = a.a22*alpha;
}
/**
*
* Performs an element by element scalar multiplication.
*
* bi = α*ai
*
*
* @param alpha the amount each element is multiplied by.
* @param a The vector that is to be scaled. Not modified.
* @param b Where the scaled matrix is stored. Modified.
*/
public static void scale( double alpha , DMatrix2 a , DMatrix2 b ) {
b.a1 = a.a1*alpha;
b.a2 = a.a2*alpha;
}
/**
*
* Performs an in-place element by element scalar division. Scalar denominator.
*
* aij = aij/α
*
*
* @param a The matrix whose elements are to be divided. Modified.
* @param alpha the amount each element is divided by.
*/
public static void divide( DMatrix2x2 a , double alpha ) {
a.a11 /= alpha; a.a12 /= alpha;
a.a21 /= alpha; a.a22 /= alpha;
}
/**
*
* Performs an in-place element by element scalar division. Scalar denominator.
*
* ai = ai/α
*
*
* @param a The vector whose elements are to be divided. Modified.
* @param alpha the amount each element is divided by.
*/
public static void divide( DMatrix2 a , double alpha ) {
a.a1 /= alpha;
a.a2 /= alpha;
}
/**
*
* Performs an element by element scalar division. Scalar denominator.
*
* bij = aij /α
*
*
* @param alpha the amount each element is divided by.
* @param a The matrix whose elements are to be divided. Not modified.
* @param b Where the results are stored. Modified.
*/
public static void divide( DMatrix2x2 a , double alpha , DMatrix2x2 b ) {
b.a11 = a.a11/alpha; b.a12 = a.a12/alpha;
b.a21 = a.a21/alpha; b.a22 = a.a22/alpha;
}
/**
*
* Performs an element by element scalar division. Scalar denominator.
*
* bi = ai /α
*
*
* @param alpha the amount each element is divided by.
* @param a The vector whose elements are to be divided. Not modified.
* @param b Where the results are stored. Modified.
*/
public static void divide( DMatrix2 a , double alpha , DMatrix2 b ) {
b.a1 = a.a1/alpha;
b.a2 = a.a2/alpha;
}
/**
*
* Changes the sign of every element in the matrix.
*
* aij = -aij
*
*
* @param a A matrix. Modified.
*/
public static void changeSign( DMatrix2x2 a )
{
a.a11 = -a.a11; a.a12 = -a.a12;
a.a21 = -a.a21; a.a22 = -a.a22;
}
/**
*
* Changes the sign of every element in the vector.
*
* ai = -ai
*
*
* @param a A vector. Modified.
*/
public static void changeSign( DMatrix2 a )
{
a.a1 = -a.a1;
a.a2 = -a.a2;
}
/**
*
* Sets every element in the matrix to the specified value.
*
* aij = value
*
*
* @param a A matrix whose elements are about to be set. Modified.
* @param v The value each element will have.
*/
public static void fill( DMatrix2x2 a , double v ) {
a.a11 = v; a.a12 = v;
a.a21 = v; a.a22 = v;
}
/**
*
* Sets every element in the vector to the specified value.
*
* ai = value
*
*
* @param a A vector whose elements are about to be set. Modified.
* @param v The value each element will have.
*/
public static void fill( DMatrix2 a , double v ) {
a.a1 = v;
a.a2 = v;
}
/**
* Extracts the row from the matrix a.
* @param a Input matrix
* @param row Which row is to be extracted
* @param out output. Storage for the extracted row. If null then a new vector will be returned.
* @return The extracted row.
*/
public static DMatrix2 extractRow( DMatrix2x2 a , int row , DMatrix2 out ) {
if( out == null) out = new DMatrix2();
switch( row ) {
case 0:
out.a1 = a.a11;
out.a2 = a.a12;
break;
case 1:
out.a1 = a.a21;
out.a2 = a.a22;
break;
default:
throw new IllegalArgumentException("Out of bounds row. row = "+row);
}
return out;
}
/**
* Extracts the column from the matrix a.
* @param a Input matrix
* @param column Which column is to be extracted
* @param out output. Storage for the extracted column. If null then a new vector will be returned.
* @return The extracted column.
*/
public static DMatrix2 extractColumn( DMatrix2x2 a , int column , DMatrix2 out ) {
if( out == null) out = new DMatrix2();
switch( column ) {
case 0:
out.a1 = a.a11;
out.a2 = a.a21;
break;
case 1:
out.a1 = a.a12;
out.a2 = a.a22;
break;
default:
throw new IllegalArgumentException("Out of bounds column. column = "+column);
}
return out;
}
}