Array2DRowRealMatrix.java
/*
* 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
*
* https://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.
*/
/*
* This is not the original file distributed by the Apache Software Foundation
* It has been modified by the Hipparchus project
*/
package org.hipparchus.linear;
import java.io.Serializable;
import org.hipparchus.exception.LocalizedCoreFormats;
import org.hipparchus.exception.MathIllegalArgumentException;
import org.hipparchus.exception.MathIllegalStateException;
import org.hipparchus.exception.NullArgumentException;
import org.hipparchus.util.FastMath;
import org.hipparchus.util.MathUtils;
/**
* Implementation of {@link RealMatrix} using a {@code double[][]} array to
* store entries.
*
*/
public class Array2DRowRealMatrix extends AbstractRealMatrix implements Serializable {
/** Serializable version identifier. */
private static final long serialVersionUID = -1067294169172445528L;
/** Entries of the matrix. */
private double[][] data;
/**
* Creates a matrix with no data
*/
public Array2DRowRealMatrix() {
// This constructor is intentionally empty. Nothing special is needed here.
}
/**
* Create a new RealMatrix with the supplied row and column dimensions.
*
* @param rowDimension Number of rows in the new matrix.
* @param columnDimension Number of columns in the new matrix.
* @throws MathIllegalArgumentException if the row or column dimension is
* not positive.
*/
public Array2DRowRealMatrix(final int rowDimension,
final int columnDimension)
throws MathIllegalArgumentException {
super(rowDimension, columnDimension);
data = new double[rowDimension][columnDimension];
}
/**
* Create a new {@code RealMatrix} using the input array as the underlying
* data array.
* <p>The input array is copied, not referenced. This constructor has
* the same effect as calling {@link #Array2DRowRealMatrix(double[][], boolean)}
* with the second argument set to {@code true}.</p>
*
* @param d Data for the new matrix.
* @throws MathIllegalArgumentException if {@code d} is not rectangular.
* @throws MathIllegalArgumentException if {@code d} row or column dimension is zero.
* @throws NullArgumentException if {@code d} is {@code null}.
* @see #Array2DRowRealMatrix(double[][], boolean)
*/
public Array2DRowRealMatrix(final double[][] d)
throws MathIllegalArgumentException, NullArgumentException {
copyIn(d);
}
/**
* Create a new RealMatrix using the input array as the underlying
* data array.
* If an array is built specially in order to be embedded in a
* RealMatrix and not used directly, the {@code copyArray} may be
* set to {@code false}. This will prevent the copying and improve
* performance as no new array will be built and no data will be copied.
*
* @param d Data for new matrix.
* @param copyArray if {@code true}, the input array will be copied,
* otherwise it will be referenced.
* @throws MathIllegalArgumentException if {@code d} is not rectangular.
* @throws MathIllegalArgumentException if {@code d} row or column dimension is zero.
* @throws NullArgumentException if {@code d} is {@code null}.
* @see #Array2DRowRealMatrix(double[][])
*/
public Array2DRowRealMatrix(final double[][] d, final boolean copyArray)
throws MathIllegalArgumentException,
NullArgumentException {
if (copyArray) {
copyIn(d);
} else {
if (d == null) {
throw new NullArgumentException();
}
final int nRows = d.length;
if (nRows == 0) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.AT_LEAST_ONE_ROW);
}
final int nCols = d[0].length;
if (nCols == 0) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.AT_LEAST_ONE_COLUMN);
}
for (int r = 1; r < nRows; r++) {
if (d[r].length != nCols) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.DIMENSIONS_MISMATCH,
d[r].length, nCols);
}
}
data = d; // NOPMD - array copy is taken care of by parameter
}
}
/**
* Create a new (column) RealMatrix using {@code v} as the
* data for the unique column of the created matrix.
* The input array is copied.
*
* @param v Column vector holding data for new matrix.
*/
public Array2DRowRealMatrix(final double[] v) {
final int nRows = v.length;
data = new double[nRows][1];
for (int row = 0; row < nRows; row++) {
data[row][0] = v[row];
}
}
/** {@inheritDoc} */
@Override
public RealMatrix createMatrix(final int rowDimension,
final int columnDimension)
throws MathIllegalArgumentException {
return new Array2DRowRealMatrix(rowDimension, columnDimension);
}
/** {@inheritDoc} */
@Override
public RealMatrix copy() {
return new Array2DRowRealMatrix(copyOut(), false);
}
/**
* Compute the sum of {@code this} and {@code m}.
*
* @param m Matrix to be added.
* @return {@code this + m}.
* @throws MathIllegalArgumentException if {@code m} is not the same
* size as {@code this}.
*/
public Array2DRowRealMatrix add(final Array2DRowRealMatrix m)
throws MathIllegalArgumentException {
// Safety check.
MatrixUtils.checkAdditionCompatible(this, m);
final int rowCount = getRowDimension();
final int columnCount = getColumnDimension();
final double[][] outData = new double[rowCount][columnCount];
for (int row = 0; row < rowCount; row++) {
final double[] dataRow = data[row];
final double[] mRow = m.data[row];
final double[] outDataRow = outData[row];
for (int col = 0; col < columnCount; col++) {
outDataRow[col] = dataRow[col] + mRow[col];
}
}
return new Array2DRowRealMatrix(outData, false);
}
/**
* Returns {@code this} minus {@code m}.
*
* @param m Matrix to be subtracted.
* @return {@code this - m}
* @throws MathIllegalArgumentException if {@code m} is not the same
* size as {@code this}.
*/
public Array2DRowRealMatrix subtract(final Array2DRowRealMatrix m)
throws MathIllegalArgumentException {
MatrixUtils.checkSubtractionCompatible(this, m);
final int rowCount = getRowDimension();
final int columnCount = getColumnDimension();
final double[][] outData = new double[rowCount][columnCount];
for (int row = 0; row < rowCount; row++) {
final double[] dataRow = data[row];
final double[] mRow = m.data[row];
final double[] outDataRow = outData[row];
for (int col = 0; col < columnCount; col++) {
outDataRow[col] = dataRow[col] - mRow[col];
}
}
return new Array2DRowRealMatrix(outData, false);
}
/**
* Returns the result of postmultiplying {@code this} by {@code m}.
*
* @param m matrix to postmultiply by
* @return {@code this * m}
* @throws MathIllegalArgumentException if
* {@code columnDimension(this) != rowDimension(m)}
*/
public Array2DRowRealMatrix multiply(final Array2DRowRealMatrix m)
throws MathIllegalArgumentException {
MatrixUtils.checkMultiplicationCompatible(this, m);
final int nRows = this.getRowDimension();
final int nCols = m.getColumnDimension();
final int nSum = this.getColumnDimension();
final double[][] outData = new double[nRows][nCols];
// Will hold a column of "m".
final double[] mCol = new double[nSum];
final double[][] mData = m.data;
// Multiply.
for (int col = 0; col < nCols; col++) {
// Copy all elements of column "col" of "m" so that
// will be in contiguous memory.
for (int mRow = 0; mRow < nSum; mRow++) {
mCol[mRow] = mData[mRow][col];
}
for (int row = 0; row < nRows; row++) {
final double[] dataRow = data[row];
double sum = 0;
for (int i = 0; i < nSum; i++) {
sum += dataRow[i] * mCol[i];
}
outData[row][col] = sum;
}
}
return new Array2DRowRealMatrix(outData, false);
}
/**
* Returns the result of postmultiplying {@code this} by {@code m^T}.
* @param m matrix to first transpose and second postmultiply by
* @return {@code this * m^T}
* @throws MathIllegalArgumentException if
* {@code columnDimension(this) != columnDimension(m)}
* @since 1.3
*/
public RealMatrix multiplyTransposed(final Array2DRowRealMatrix m)
throws MathIllegalArgumentException {
MatrixUtils.checkSameColumnDimension(this, m);
final int nRows = this.getRowDimension();
final int nCols = m.getRowDimension();
final int nSum = this.getColumnDimension();
final RealMatrix out = MatrixUtils.createRealMatrix(nRows, nCols);
final double[][] mData = m.data;
// Multiply.
for (int col = 0; col < nCols; col++) {
for (int row = 0; row < nRows; row++) {
final double[] dataRow = data[row];
final double[] mRow = mData[col];
double sum = 0;
for (int i = 0; i < nSum; i++) {
sum += dataRow[i] * mRow[i];
}
out.setEntry(row, col, sum);
}
}
return out;
}
/** {@inheritDoc} */
@Override
public RealMatrix multiplyTransposed(final RealMatrix m) {
if (m instanceof Array2DRowRealMatrix) {
return multiplyTransposed((Array2DRowRealMatrix) m);
} else {
MatrixUtils.checkSameColumnDimension(this, m);
final int nRows = this.getRowDimension();
final int nCols = m.getRowDimension();
final int nSum = this.getColumnDimension();
final RealMatrix out = MatrixUtils.createRealMatrix(nRows, nCols);
// Multiply.
for (int col = 0; col < nCols; col++) {
for (int row = 0; row < nRows; row++) {
final double[] dataRow = data[row];
double sum = 0;
for (int i = 0; i < nSum; i++) {
sum += dataRow[i] * m.getEntry(col, i);
}
out.setEntry(row, col, sum);
}
}
return out;
}
}
/**
* Returns the result of postmultiplying {@code this^T} by {@code m}.
* @param m matrix to postmultiply by
* @return {@code this^T * m}
* @throws MathIllegalArgumentException if
* {@code columnDimension(this) != columnDimension(m)}
* @since 1.3
*/
public RealMatrix transposeMultiply(final Array2DRowRealMatrix m)
throws MathIllegalArgumentException {
MatrixUtils.checkSameRowDimension(this, m);
final int nRows = this.getColumnDimension();
final int nCols = m.getColumnDimension();
final int nSum = this.getRowDimension();
final RealMatrix out = MatrixUtils.createRealMatrix(nRows, nCols);
final double[][] mData = m.data;
// Multiply.
for (int k = 0; k < nSum; k++) {
final double[] dataK = data[k];
final double[] mK = mData[k];
for (int row = 0; row < nRows; row++) {
final double dataIRow = dataK[row];
for (int col = 0; col < nCols; col++) {
out.addToEntry(row, col, dataIRow * mK[col]);
}
}
}
return out;
}
/** {@inheritDoc} */
@Override
public RealMatrix transposeMultiply(final RealMatrix m) {
if (m instanceof Array2DRowRealMatrix) {
return transposeMultiply((Array2DRowRealMatrix) m);
} else {
MatrixUtils.checkSameRowDimension(this, m);
final int nRows = this.getColumnDimension();
final int nCols = m.getColumnDimension();
final int nSum = this.getRowDimension();
final RealMatrix out = MatrixUtils.createRealMatrix(nRows, nCols);
// Multiply.
for (int k = 0; k < nSum; k++) {
final double[] dataK = data[k];
for (int row = 0; row < nRows; row++) {
final double dataIRow = dataK[row];
for (int col = 0; col < nCols; col++) {
out.addToEntry(row, col, dataIRow * m.getEntry(k, col));
}
}
}
return out;
}
}
/** {@inheritDoc} */
@Override
public double[][] getData() {
return copyOut();
}
/**
* Get a reference to the underlying data array.
*
* @return 2-dimensional array of entries.
*/
public double[][] getDataRef() {
return data; // NOPMD - returning an internal array is intentional and documented here
}
/** {@inheritDoc} */
@Override
public void setSubMatrix(final double[][] subMatrix, final int row,
final int column)
throws MathIllegalArgumentException, NullArgumentException {
if (data == null) {
if (row > 0) {
throw new MathIllegalStateException(LocalizedCoreFormats.FIRST_ROWS_NOT_INITIALIZED_YET, row);
}
if (column > 0) {
throw new MathIllegalStateException(LocalizedCoreFormats.FIRST_COLUMNS_NOT_INITIALIZED_YET, column);
}
MathUtils.checkNotNull(subMatrix);
final int nRows = subMatrix.length;
if (nRows == 0) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.AT_LEAST_ONE_ROW);
}
final int nCols = subMatrix[0].length;
if (nCols == 0) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.AT_LEAST_ONE_COLUMN);
}
data = new double[subMatrix.length][nCols];
for (int i = 0; i < data.length; ++i) {
if (subMatrix[i].length != nCols) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.DIMENSIONS_MISMATCH,
subMatrix[i].length, nCols);
}
System.arraycopy(subMatrix[i], 0, data[i + row], column, nCols);
}
} else {
super.setSubMatrix(subMatrix, row, column);
}
}
/** {@inheritDoc} */
@Override
public double getEntry(final int row, final int column)
throws MathIllegalArgumentException {
try {
return data[row][column];
} catch (IndexOutOfBoundsException e) {
// throw the exact cause of the exception
MatrixUtils.checkMatrixIndex(this, row, column);
// should never happen
throw e;
}
}
/** {@inheritDoc} */
@Override
public void setEntry(final int row, final int column, final double value)
throws MathIllegalArgumentException {
MatrixUtils.checkMatrixIndex(this, row, column);
data[row][column] = value;
}
/** {@inheritDoc} */
@Override
public void addToEntry(final int row, final int column,
final double increment)
throws MathIllegalArgumentException {
MatrixUtils.checkMatrixIndex(this, row, column);
data[row][column] += increment;
}
/** {@inheritDoc} */
@Override
public void multiplyEntry(final int row, final int column,
final double factor)
throws MathIllegalArgumentException {
MatrixUtils.checkMatrixIndex(this, row, column);
data[row][column] *= factor;
}
/** {@inheritDoc} */
@Override
public int getRowDimension() {
return (data == null) ? 0 : data.length;
}
/** {@inheritDoc} */
@Override
public int getColumnDimension() {
return ((data == null) || (data[0] == null)) ? 0 : data[0].length;
}
/** {@inheritDoc} */
@Override
public double[] operate(final double[] v)
throws MathIllegalArgumentException {
final int nRows = this.getRowDimension();
final int nCols = this.getColumnDimension();
if (v.length != nCols) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.DIMENSIONS_MISMATCH,
v.length, nCols);
}
final double[] out = new double[nRows];
for (int row = 0; row < nRows; row++) {
final double[] dataRow = data[row];
double sum = 0;
for (int i = 0; i < nCols; i++) {
sum += dataRow[i] * v[i];
}
out[row] = sum;
}
return out;
}
/** {@inheritDoc} */
@Override
public double[] preMultiply(final double[] v)
throws MathIllegalArgumentException {
final int nRows = getRowDimension();
final int nCols = getColumnDimension();
if (v.length != nRows) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.DIMENSIONS_MISMATCH,
v.length, nRows);
}
final double[] out = new double[nCols];
for (int col = 0; col < nCols; ++col) {
double sum = 0;
for (int i = 0; i < nRows; ++i) {
sum += data[i][col] * v[i];
}
out[col] = sum;
}
return out;
}
/** {@inheritDoc} */
@Override
public RealMatrix getSubMatrix(final int startRow, final int endRow,
final int startColumn, final int endColumn)
throws MathIllegalArgumentException {
MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn);
final int rowCount = endRow - startRow + 1;
final int columnCount = endColumn - startColumn + 1;
final double[][] outData = new double[rowCount][columnCount];
for (int i = 0; i < rowCount; ++i) {
System.arraycopy(data[startRow + i], startColumn, outData[i], 0, columnCount);
}
Array2DRowRealMatrix subMatrix = new Array2DRowRealMatrix();
subMatrix.data = outData;
return subMatrix;
}
/** {@inheritDoc} */
@Override
public double walkInRowOrder(final RealMatrixChangingVisitor visitor) {
final int rows = getRowDimension();
final int columns = getColumnDimension();
visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
for (int i = 0; i < rows; ++i) {
final double[] rowI = data[i];
for (int j = 0; j < columns; ++j) {
rowI[j] = visitor.visit(i, j, rowI[j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInRowOrder(final RealMatrixPreservingVisitor visitor) {
final int rows = getRowDimension();
final int columns = getColumnDimension();
visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
for (int i = 0; i < rows; ++i) {
final double[] rowI = data[i];
for (int j = 0; j < columns; ++j) {
visitor.visit(i, j, rowI[j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInRowOrder(final RealMatrixChangingVisitor visitor,
final int startRow, final int endRow,
final int startColumn, final int endColumn)
throws MathIllegalArgumentException {
MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn);
visitor.start(getRowDimension(), getColumnDimension(),
startRow, endRow, startColumn, endColumn);
for (int i = startRow; i <= endRow; ++i) {
final double[] rowI = data[i];
for (int j = startColumn; j <= endColumn; ++j) {
rowI[j] = visitor.visit(i, j, rowI[j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInRowOrder(final RealMatrixPreservingVisitor visitor,
final int startRow, final int endRow,
final int startColumn, final int endColumn)
throws MathIllegalArgumentException {
MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn);
visitor.start(getRowDimension(), getColumnDimension(),
startRow, endRow, startColumn, endColumn);
for (int i = startRow; i <= endRow; ++i) {
final double[] rowI = data[i];
for (int j = startColumn; j <= endColumn; ++j) {
visitor.visit(i, j, rowI[j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInColumnOrder(final RealMatrixChangingVisitor visitor) {
final int rows = getRowDimension();
final int columns = getColumnDimension();
visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
for (int j = 0; j < columns; ++j) {
for (int i = 0; i < rows; ++i) {
final double[] rowI = data[i];
rowI[j] = visitor.visit(i, j, rowI[j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInColumnOrder(final RealMatrixPreservingVisitor visitor) {
final int rows = getRowDimension();
final int columns = getColumnDimension();
visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
for (int j = 0; j < columns; ++j) {
for (int i = 0; i < rows; ++i) {
visitor.visit(i, j, data[i][j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInColumnOrder(final RealMatrixChangingVisitor visitor,
final int startRow, final int endRow,
final int startColumn, final int endColumn)
throws MathIllegalArgumentException {
MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn);
visitor.start(getRowDimension(), getColumnDimension(),
startRow, endRow, startColumn, endColumn);
for (int j = startColumn; j <= endColumn; ++j) {
for (int i = startRow; i <= endRow; ++i) {
final double[] rowI = data[i];
rowI[j] = visitor.visit(i, j, rowI[j]);
}
}
return visitor.end();
}
/** {@inheritDoc} */
@Override
public double walkInColumnOrder(final RealMatrixPreservingVisitor visitor,
final int startRow, final int endRow,
final int startColumn, final int endColumn)
throws MathIllegalArgumentException {
MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn);
visitor.start(getRowDimension(), getColumnDimension(),
startRow, endRow, startColumn, endColumn);
for (int j = startColumn; j <= endColumn; ++j) {
for (int i = startRow; i <= endRow; ++i) {
visitor.visit(i, j, data[i][j]);
}
}
return visitor.end();
}
/**
* Get a fresh copy of the underlying data array.
*
* @return a copy of the underlying data array.
*/
private double[][] copyOut() {
final int nRows = this.getRowDimension();
final double[][] out = new double[nRows][this.getColumnDimension()];
// can't copy 2-d array in one shot, otherwise get row references
for (int i = 0; i < nRows; i++) {
System.arraycopy(data[i], 0, out[i], 0, data[i].length);
}
return out;
}
/**
* Replace data with a fresh copy of the input array.
*
* @param in Data to copy.
* @throws MathIllegalArgumentException if the input array is empty.
* @throws MathIllegalArgumentException if the input array is not rectangular.
* @throws NullArgumentException if the input array is {@code null}.
*/
private void copyIn(final double[][] in)
throws MathIllegalArgumentException, NullArgumentException {
setSubMatrix(in, 0, 0);
}
/** {@inheritDoc} */
@Override
public double[] getRow(final int row) throws MathIllegalArgumentException {
MatrixUtils.checkRowIndex(this, row);
final int nCols = getColumnDimension();
final double[] out = new double[nCols];
System.arraycopy(data[row], 0, out, 0, nCols);
return out;
}
/** {@inheritDoc} */
@Override
public void setRow(final int row, final double[] array)
throws MathIllegalArgumentException {
MatrixUtils.checkRowIndex(this, row);
final int nCols = getColumnDimension();
if (array.length != nCols) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.DIMENSIONS_MISMATCH_2x2,
1, array.length, 1, nCols);
}
System.arraycopy(array, 0, data[row], 0, nCols);
}
/**
* Kronecker product of the current matrix and the parameter matrix.
*
* @param b matrix to post Kronecker-multiply by
* @return this ⨂ b
*/
public RealMatrix kroneckerProduct(final RealMatrix b) {
final int m = getRowDimension();
final int n = getColumnDimension();
final int p = b.getRowDimension();
final int q = b.getColumnDimension();
final RealMatrix kroneckerProduct = MatrixUtils.createRealMatrix(m * p, n * q);
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
kroneckerProduct.setSubMatrix(b.scalarMultiply(getEntry(i, j)) .getData(), i * p, j * q);
}
}
return kroneckerProduct;
}
/**
* Transforms a matrix in a vector (Vectorization).
* @return a one column matrix
*/
public RealMatrix stack() {
final int m = getRowDimension();
final int n = getColumnDimension();
final RealMatrix stacked = MatrixUtils.createRealMatrix(m * n, 1);
for (int i = 0; i < m; i++) {
stacked.setSubMatrix(getColumnMatrix(i).getData(), i * n, 0);
}
return stacked;
}
/**
* Transforms a one-column stacked matrix into a squared matrix (devectorization).
* @return square matrix
*/
public RealMatrix unstackSquare() {
final int m = getRowDimension();
final int n = getColumnDimension();
final int s = (int) FastMath.round(FastMath.sqrt(m));
if (n != 1) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.DIMENSIONS_MISMATCH, n, 1);
}
if (s * s != m) {
throw new MathIllegalArgumentException(LocalizedCoreFormats.NON_SQUARE_MATRIX, s, ((double) m) / s);
}
final RealMatrix unstacked = MatrixUtils.createRealMatrix(s, s);
for (int i = 0; i < s; i++) {
unstacked.setColumnMatrix(i, getSubMatrix(i * s, i * s + s - 1, 0, 0));
}
return unstacked;
}
}