Java tutorial
/* * 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 * * 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.apache.commons.math.linear; import org.apache.commons.math.MathRuntimeException; import org.apache.commons.math.linear.MatrixVisitorException; import org.apache.commons.math.exception.util.LocalizedFormats; import org.apache.commons.math.util.MathUtils; import org.apache.commons.math.util.FastMath; /** * Basic implementation of RealMatrix methods regardless of the underlying storage. * <p>All the methods implemented here use {@link #getEntry(int, int)} to access * matrix elements. Derived class can provide faster implementations. </p> * * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 fvr. 2011) $ * @since 2.0 */ public abstract class AbstractRealMatrix implements RealMatrix { /** Cached LU solver. * @deprecated as of release 2.0, since all methods using this are deprecated */ @Deprecated private DecompositionSolver lu; /** * Creates a matrix with no data */ protected AbstractRealMatrix() { lu = null; } /** * Create a new RealMatrix with the supplied row and column dimensions. * * @param rowDimension the number of rows in the new matrix * @param columnDimension the number of columns in the new matrix * @throws IllegalArgumentException if row or column dimension is not positive */ protected AbstractRealMatrix(final int rowDimension, final int columnDimension) throws IllegalArgumentException { if (rowDimension < 1) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.INSUFFICIENT_DIMENSION, rowDimension, 1); } if (columnDimension <= 0) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.INSUFFICIENT_DIMENSION, columnDimension, 1); } lu = null; } /** {@inheritDoc} */ public abstract RealMatrix createMatrix(final int rowDimension, final int columnDimension) throws IllegalArgumentException; /** {@inheritDoc} */ public abstract RealMatrix copy(); /** {@inheritDoc} */ public RealMatrix add(RealMatrix m) throws IllegalArgumentException { // safety check MatrixUtils.checkAdditionCompatible(this, m); final int rowCount = getRowDimension(); final int columnCount = getColumnDimension(); final RealMatrix out = createMatrix(rowCount, columnCount); for (int row = 0; row < rowCount; ++row) { for (int col = 0; col < columnCount; ++col) { out.setEntry(row, col, getEntry(row, col) + m.getEntry(row, col)); } } return out; } /** {@inheritDoc} */ public RealMatrix subtract(final RealMatrix m) throws IllegalArgumentException { // safety check MatrixUtils.checkSubtractionCompatible(this, m); final int rowCount = getRowDimension(); final int columnCount = getColumnDimension(); final RealMatrix out = createMatrix(rowCount, columnCount); for (int row = 0; row < rowCount; ++row) { for (int col = 0; col < columnCount; ++col) { out.setEntry(row, col, getEntry(row, col) - m.getEntry(row, col)); } } return out; } /** {@inheritDoc} */ public RealMatrix scalarAdd(final double d) { final int rowCount = getRowDimension(); final int columnCount = getColumnDimension(); final RealMatrix out = createMatrix(rowCount, columnCount); for (int row = 0; row < rowCount; ++row) { for (int col = 0; col < columnCount; ++col) { out.setEntry(row, col, getEntry(row, col) + d); } } return out; } /** {@inheritDoc} */ public RealMatrix scalarMultiply(final double d) { final int rowCount = getRowDimension(); final int columnCount = getColumnDimension(); final RealMatrix out = createMatrix(rowCount, columnCount); for (int row = 0; row < rowCount; ++row) { for (int col = 0; col < columnCount; ++col) { out.setEntry(row, col, getEntry(row, col) * d); } } return out; } /** {@inheritDoc} */ public RealMatrix multiply(final RealMatrix m) throws IllegalArgumentException { // safety check MatrixUtils.checkMultiplicationCompatible(this, m); final int nRows = getRowDimension(); final int nCols = m.getColumnDimension(); final int nSum = getColumnDimension(); final RealMatrix out = createMatrix(nRows, nCols); for (int row = 0; row < nRows; ++row) { for (int col = 0; col < nCols; ++col) { double sum = 0; for (int i = 0; i < nSum; ++i) { sum += getEntry(row, i) * m.getEntry(i, col); } out.setEntry(row, col, sum); } } return out; } /** {@inheritDoc} */ public RealMatrix preMultiply(final RealMatrix m) throws IllegalArgumentException { return m.multiply(this); } /** {@inheritDoc} */ public double[][] getData() { final double[][] data = new double[getRowDimension()][getColumnDimension()]; for (int i = 0; i < data.length; ++i) { final double[] dataI = data[i]; for (int j = 0; j < dataI.length; ++j) { dataI[j] = getEntry(i, j); } } return data; } /** {@inheritDoc} */ public double getNorm() { return walkInColumnOrder(new RealMatrixPreservingVisitor() { /** Last row index. */ private double endRow; /** Sum of absolute values on one column. */ private double columnSum; /** Maximal sum across all columns. */ private double maxColSum; /** {@inheritDoc} */ public void start(final int rows, final int columns, final int startRow, final int endRow, final int startColumn, final int endColumn) { this.endRow = endRow; columnSum = 0; maxColSum = 0; } /** {@inheritDoc} */ public void visit(final int row, final int column, final double value) { columnSum += FastMath.abs(value); if (row == endRow) { maxColSum = FastMath.max(maxColSum, columnSum); columnSum = 0; } } /** {@inheritDoc} */ public double end() { return maxColSum; } }); } /** {@inheritDoc} */ public double getFrobeniusNorm() { return walkInOptimizedOrder(new RealMatrixPreservingVisitor() { /** Sum of squared entries. */ private double sum; /** {@inheritDoc} */ public void start(final int rows, final int columns, final int startRow, final int endRow, final int startColumn, final int endColumn) { sum = 0; } /** {@inheritDoc} */ public void visit(final int row, final int column, final double value) { sum += value * value; } /** {@inheritDoc} */ public double end() { return FastMath.sqrt(sum); } }); } /** {@inheritDoc} */ public RealMatrix getSubMatrix(final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException { MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn); final RealMatrix subMatrix = createMatrix(endRow - startRow + 1, endColumn - startColumn + 1); for (int i = startRow; i <= endRow; ++i) { for (int j = startColumn; j <= endColumn; ++j) { subMatrix.setEntry(i - startRow, j - startColumn, getEntry(i, j)); } } return subMatrix; } /** {@inheritDoc} */ public RealMatrix getSubMatrix(final int[] selectedRows, final int[] selectedColumns) throws MatrixIndexException { // safety checks MatrixUtils.checkSubMatrixIndex(this, selectedRows, selectedColumns); // copy entries final RealMatrix subMatrix = createMatrix(selectedRows.length, selectedColumns.length); subMatrix.walkInOptimizedOrder(new DefaultRealMatrixChangingVisitor() { /** {@inheritDoc} */ @Override public double visit(final int row, final int column, final double value) { return getEntry(selectedRows[row], selectedColumns[column]); } }); return subMatrix; } /** {@inheritDoc} */ public void copySubMatrix(final int startRow, final int endRow, final int startColumn, final int endColumn, final double[][] destination) throws MatrixIndexException, IllegalArgumentException { // safety checks MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn); final int rowsCount = endRow + 1 - startRow; final int columnsCount = endColumn + 1 - startColumn; if ((destination.length < rowsCount) || (destination[0].length < columnsCount)) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, destination.length, destination[0].length, rowsCount, columnsCount); } // copy entries walkInOptimizedOrder(new DefaultRealMatrixPreservingVisitor() { /** Initial row index. */ private int startRow; /** Initial column index. */ private int startColumn; /** {@inheritDoc} */ @Override public void start(final int rows, final int columns, final int startRow, final int endRow, final int startColumn, final int endColumn) { this.startRow = startRow; this.startColumn = startColumn; } /** {@inheritDoc} */ @Override public void visit(final int row, final int column, final double value) { destination[row - startRow][column - startColumn] = value; } }, startRow, endRow, startColumn, endColumn); } /** {@inheritDoc} */ public void copySubMatrix(int[] selectedRows, int[] selectedColumns, double[][] destination) throws MatrixIndexException, IllegalArgumentException { // safety checks MatrixUtils.checkSubMatrixIndex(this, selectedRows, selectedColumns); if ((destination.length < selectedRows.length) || (destination[0].length < selectedColumns.length)) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, destination.length, destination[0].length, selectedRows.length, selectedColumns.length); } // copy entries for (int i = 0; i < selectedRows.length; i++) { final double[] destinationI = destination[i]; for (int j = 0; j < selectedColumns.length; j++) { destinationI[j] = getEntry(selectedRows[i], selectedColumns[j]); } } } /** {@inheritDoc} */ public void setSubMatrix(final double[][] subMatrix, final int row, final int column) throws MatrixIndexException { final int nRows = subMatrix.length; if (nRows == 0) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.AT_LEAST_ONE_ROW); } final int nCols = subMatrix[0].length; if (nCols == 0) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.AT_LEAST_ONE_COLUMN); } for (int r = 1; r < nRows; ++r) { if (subMatrix[r].length != nCols) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.DIFFERENT_ROWS_LENGTHS, nCols, subMatrix[r].length); } } MatrixUtils.checkRowIndex(this, row); MatrixUtils.checkColumnIndex(this, column); MatrixUtils.checkRowIndex(this, nRows + row - 1); MatrixUtils.checkColumnIndex(this, nCols + column - 1); for (int i = 0; i < nRows; ++i) { for (int j = 0; j < nCols; ++j) { setEntry(row + i, column + j, subMatrix[i][j]); } } lu = null; } /** {@inheritDoc} */ public RealMatrix getRowMatrix(final int row) throws MatrixIndexException { MatrixUtils.checkRowIndex(this, row); final int nCols = getColumnDimension(); final RealMatrix out = createMatrix(1, nCols); for (int i = 0; i < nCols; ++i) { out.setEntry(0, i, getEntry(row, i)); } return out; } /** {@inheritDoc} */ public void setRowMatrix(final int row, final RealMatrix matrix) throws MatrixIndexException, InvalidMatrixException { MatrixUtils.checkRowIndex(this, row); final int nCols = getColumnDimension(); if ((matrix.getRowDimension() != 1) || (matrix.getColumnDimension() != nCols)) { throw new InvalidMatrixException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, matrix.getRowDimension(), matrix.getColumnDimension(), 1, nCols); } for (int i = 0; i < nCols; ++i) { setEntry(row, i, matrix.getEntry(0, i)); } } /** {@inheritDoc} */ public RealMatrix getColumnMatrix(final int column) throws MatrixIndexException { MatrixUtils.checkColumnIndex(this, column); final int nRows = getRowDimension(); final RealMatrix out = createMatrix(nRows, 1); for (int i = 0; i < nRows; ++i) { out.setEntry(i, 0, getEntry(i, column)); } return out; } /** {@inheritDoc} */ public void setColumnMatrix(final int column, final RealMatrix matrix) throws MatrixIndexException, InvalidMatrixException { MatrixUtils.checkColumnIndex(this, column); final int nRows = getRowDimension(); if ((matrix.getRowDimension() != nRows) || (matrix.getColumnDimension() != 1)) { throw new InvalidMatrixException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, matrix.getRowDimension(), matrix.getColumnDimension(), nRows, 1); } for (int i = 0; i < nRows; ++i) { setEntry(i, column, matrix.getEntry(i, 0)); } } /** {@inheritDoc} */ public RealVector getRowVector(final int row) throws MatrixIndexException { return new ArrayRealVector(getRow(row), false); } /** {@inheritDoc} */ public void setRowVector(final int row, final RealVector vector) throws MatrixIndexException, InvalidMatrixException { MatrixUtils.checkRowIndex(this, row); final int nCols = getColumnDimension(); if (vector.getDimension() != nCols) { throw new InvalidMatrixException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, 1, vector.getDimension(), 1, nCols); } for (int i = 0; i < nCols; ++i) { setEntry(row, i, vector.getEntry(i)); } } /** {@inheritDoc} */ public RealVector getColumnVector(final int column) throws MatrixIndexException { return new ArrayRealVector(getColumn(column), false); } /** {@inheritDoc} */ public void setColumnVector(final int column, final RealVector vector) throws MatrixIndexException, InvalidMatrixException { MatrixUtils.checkColumnIndex(this, column); final int nRows = getRowDimension(); if (vector.getDimension() != nRows) { throw new InvalidMatrixException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, vector.getDimension(), 1, nRows, 1); } for (int i = 0; i < nRows; ++i) { setEntry(i, column, vector.getEntry(i)); } } /** {@inheritDoc} */ public double[] getRow(final int row) throws MatrixIndexException { MatrixUtils.checkRowIndex(this, row); final int nCols = getColumnDimension(); final double[] out = new double[nCols]; for (int i = 0; i < nCols; ++i) { out[i] = getEntry(row, i); } return out; } /** {@inheritDoc} */ public void setRow(final int row, final double[] array) throws MatrixIndexException, InvalidMatrixException { MatrixUtils.checkRowIndex(this, row); final int nCols = getColumnDimension(); if (array.length != nCols) { throw new InvalidMatrixException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, 1, array.length, 1, nCols); } for (int i = 0; i < nCols; ++i) { setEntry(row, i, array[i]); } } /** {@inheritDoc} */ public double[] getColumn(final int column) throws MatrixIndexException { MatrixUtils.checkColumnIndex(this, column); final int nRows = getRowDimension(); final double[] out = new double[nRows]; for (int i = 0; i < nRows; ++i) { out[i] = getEntry(i, column); } return out; } /** {@inheritDoc} */ public void setColumn(final int column, final double[] array) throws MatrixIndexException, InvalidMatrixException { MatrixUtils.checkColumnIndex(this, column); final int nRows = getRowDimension(); if (array.length != nRows) { throw new InvalidMatrixException(LocalizedFormats.DIMENSIONS_MISMATCH_2x2, array.length, 1, nRows, 1); } for (int i = 0; i < nRows; ++i) { setEntry(i, column, array[i]); } } /** {@inheritDoc} */ public abstract double getEntry(int row, int column) throws MatrixIndexException; /** {@inheritDoc} */ public abstract void setEntry(int row, int column, double value) throws MatrixIndexException; /** {@inheritDoc} */ public abstract void addToEntry(int row, int column, double increment) throws MatrixIndexException; /** {@inheritDoc} */ public abstract void multiplyEntry(int row, int column, double factor) throws MatrixIndexException; /** {@inheritDoc} */ public RealMatrix transpose() { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); final RealMatrix out = createMatrix(nCols, nRows); walkInOptimizedOrder(new DefaultRealMatrixPreservingVisitor() { /** {@inheritDoc} */ @Override public void visit(final int row, final int column, final double value) { out.setEntry(column, row, value); } }); return out; } /** {@inheritDoc} */ @Deprecated public RealMatrix inverse() throws InvalidMatrixException { if (lu == null) { lu = new LUDecompositionImpl(this, MathUtils.SAFE_MIN).getSolver(); } return lu.getInverse(); } /** {@inheritDoc} */ @Deprecated public double getDeterminant() throws InvalidMatrixException { return new LUDecompositionImpl(this, MathUtils.SAFE_MIN).getDeterminant(); } /** {@inheritDoc} */ public boolean isSquare() { return getColumnDimension() == getRowDimension(); } /** {@inheritDoc} */ @Deprecated public boolean isSingular() { if (lu == null) { lu = new LUDecompositionImpl(this, MathUtils.SAFE_MIN).getSolver(); } return !lu.isNonSingular(); } /** {@inheritDoc} */ public abstract int getRowDimension(); /** {@inheritDoc} */ public abstract int getColumnDimension(); /** {@inheritDoc} */ public double getTrace() throws NonSquareMatrixException { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); if (nRows != nCols) { throw new NonSquareMatrixException(nRows, nCols); } double trace = 0; for (int i = 0; i < nRows; ++i) { trace += getEntry(i, i); } return trace; } /** {@inheritDoc} */ public double[] operate(final double[] v) throws IllegalArgumentException { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); if (v.length != nCols) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.VECTOR_LENGTH_MISMATCH, v.length, nCols); } final double[] out = new double[nRows]; for (int row = 0; row < nRows; ++row) { double sum = 0; for (int i = 0; i < nCols; ++i) { sum += getEntry(row, i) * v[i]; } out[row] = sum; } return out; } /** {@inheritDoc} */ public RealVector operate(final RealVector v) throws IllegalArgumentException { try { return new ArrayRealVector(operate(((ArrayRealVector) v).getDataRef()), false); } catch (ClassCastException cce) { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); if (v.getDimension() != nCols) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.VECTOR_LENGTH_MISMATCH, v.getDimension(), nCols); } final double[] out = new double[nRows]; for (int row = 0; row < nRows; ++row) { double sum = 0; for (int i = 0; i < nCols; ++i) { sum += getEntry(row, i) * v.getEntry(i); } out[row] = sum; } return new ArrayRealVector(out, false); } } /** {@inheritDoc} */ public double[] preMultiply(final double[] v) throws IllegalArgumentException { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); if (v.length != nRows) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.VECTOR_LENGTH_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 += getEntry(i, col) * v[i]; } out[col] = sum; } return out; } /** {@inheritDoc} */ public RealVector preMultiply(final RealVector v) throws IllegalArgumentException { try { return new ArrayRealVector(preMultiply(((ArrayRealVector) v).getDataRef()), false); } catch (ClassCastException cce) { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); if (v.getDimension() != nRows) { throw MathRuntimeException.createIllegalArgumentException(LocalizedFormats.VECTOR_LENGTH_MISMATCH, v.getDimension(), 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 += getEntry(i, col) * v.getEntry(i); } out[col] = sum; } return new ArrayRealVector(out); } } /** {@inheritDoc} */ public double walkInRowOrder(final RealMatrixChangingVisitor visitor) throws MatrixVisitorException { final int rows = getRowDimension(); final int columns = getColumnDimension(); visitor.start(rows, columns, 0, rows - 1, 0, columns - 1); for (int row = 0; row < rows; ++row) { for (int column = 0; column < columns; ++column) { final double oldValue = getEntry(row, column); final double newValue = visitor.visit(row, column, oldValue); setEntry(row, column, newValue); } } lu = null; return visitor.end(); } /** {@inheritDoc} */ public double walkInRowOrder(final RealMatrixPreservingVisitor visitor) throws MatrixVisitorException { final int rows = getRowDimension(); final int columns = getColumnDimension(); visitor.start(rows, columns, 0, rows - 1, 0, columns - 1); for (int row = 0; row < rows; ++row) { for (int column = 0; column < columns; ++column) { visitor.visit(row, column, getEntry(row, column)); } } return visitor.end(); } /** {@inheritDoc} */ public double walkInRowOrder(final RealMatrixChangingVisitor visitor, final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException, MatrixVisitorException { MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn); visitor.start(getRowDimension(), getColumnDimension(), startRow, endRow, startColumn, endColumn); for (int row = startRow; row <= endRow; ++row) { for (int column = startColumn; column <= endColumn; ++column) { final double oldValue = getEntry(row, column); final double newValue = visitor.visit(row, column, oldValue); setEntry(row, column, newValue); } } lu = null; return visitor.end(); } /** {@inheritDoc} */ public double walkInRowOrder(final RealMatrixPreservingVisitor visitor, final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException, MatrixVisitorException { MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn); visitor.start(getRowDimension(), getColumnDimension(), startRow, endRow, startColumn, endColumn); for (int row = startRow; row <= endRow; ++row) { for (int column = startColumn; column <= endColumn; ++column) { visitor.visit(row, column, getEntry(row, column)); } } return visitor.end(); } /** {@inheritDoc} */ public double walkInColumnOrder(final RealMatrixChangingVisitor visitor) throws MatrixVisitorException { final int rows = getRowDimension(); final int columns = getColumnDimension(); visitor.start(rows, columns, 0, rows - 1, 0, columns - 1); for (int column = 0; column < columns; ++column) { for (int row = 0; row < rows; ++row) { final double oldValue = getEntry(row, column); final double newValue = visitor.visit(row, column, oldValue); setEntry(row, column, newValue); } } lu = null; return visitor.end(); } /** {@inheritDoc} */ public double walkInColumnOrder(final RealMatrixPreservingVisitor visitor) throws MatrixVisitorException { final int rows = getRowDimension(); final int columns = getColumnDimension(); visitor.start(rows, columns, 0, rows - 1, 0, columns - 1); for (int column = 0; column < columns; ++column) { for (int row = 0; row < rows; ++row) { visitor.visit(row, column, getEntry(row, column)); } } return visitor.end(); } /** {@inheritDoc} */ public double walkInColumnOrder(final RealMatrixChangingVisitor visitor, final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException, MatrixVisitorException { MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn); visitor.start(getRowDimension(), getColumnDimension(), startRow, endRow, startColumn, endColumn); for (int column = startColumn; column <= endColumn; ++column) { for (int row = startRow; row <= endRow; ++row) { final double oldValue = getEntry(row, column); final double newValue = visitor.visit(row, column, oldValue); setEntry(row, column, newValue); } } lu = null; return visitor.end(); } /** {@inheritDoc} */ public double walkInColumnOrder(final RealMatrixPreservingVisitor visitor, final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException, MatrixVisitorException { MatrixUtils.checkSubMatrixIndex(this, startRow, endRow, startColumn, endColumn); visitor.start(getRowDimension(), getColumnDimension(), startRow, endRow, startColumn, endColumn); for (int column = startColumn; column <= endColumn; ++column) { for (int row = startRow; row <= endRow; ++row) { visitor.visit(row, column, getEntry(row, column)); } } return visitor.end(); } /** {@inheritDoc} */ public double walkInOptimizedOrder(final RealMatrixChangingVisitor visitor) throws MatrixVisitorException { return walkInRowOrder(visitor); } /** {@inheritDoc} */ public double walkInOptimizedOrder(final RealMatrixPreservingVisitor visitor) throws MatrixVisitorException { return walkInRowOrder(visitor); } /** {@inheritDoc} */ public double walkInOptimizedOrder(final RealMatrixChangingVisitor visitor, final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException, MatrixVisitorException { return walkInRowOrder(visitor, startRow, endRow, startColumn, endColumn); } /** {@inheritDoc} */ public double walkInOptimizedOrder(final RealMatrixPreservingVisitor visitor, final int startRow, final int endRow, final int startColumn, final int endColumn) throws MatrixIndexException, MatrixVisitorException { return walkInRowOrder(visitor, startRow, endRow, startColumn, endColumn); } /** {@inheritDoc} */ @Deprecated public double[] solve(final double[] b) throws IllegalArgumentException, InvalidMatrixException { if (lu == null) { lu = new LUDecompositionImpl(this, MathUtils.SAFE_MIN).getSolver(); } return lu.solve(b); } /** {@inheritDoc} */ @Deprecated public RealMatrix solve(final RealMatrix b) throws IllegalArgumentException, InvalidMatrixException { if (lu == null) { lu = new LUDecompositionImpl(this, MathUtils.SAFE_MIN).getSolver(); } return lu.solve(b); } /** * Computes a new * <a href="http://www.math.gatech.edu/~bourbaki/math2601/Web-notes/2num.pdf"> * LU decomposition</a> for this matrix, storing the result for use by other methods. * <p> * <strong>Implementation Note</strong>:<br> * Uses <a href="http://www.damtp.cam.ac.uk/user/fdl/people/sd/lectures/nummeth98/linear.htm"> * Crout's algorithm</a>, with partial pivoting.</p> * <p> * <strong>Usage Note</strong>:<br> * This method should rarely be invoked directly. Its only use is * to force recomputation of the LU decomposition when changes have been * made to the underlying data using direct array references. Changes * made using setXxx methods will trigger recomputation when needed * automatically.</p> * * @throws InvalidMatrixException if the matrix is non-square or singular. * @deprecated as of release 2.0, replaced by {@link LUDecomposition} */ @Deprecated public void luDecompose() throws InvalidMatrixException { if (lu == null) { lu = new LUDecompositionImpl(this, MathUtils.SAFE_MIN).getSolver(); } } /** * Get a string representation for this matrix. * @return a string representation for this matrix */ @Override public String toString() { final int nRows = getRowDimension(); final int nCols = getColumnDimension(); final StringBuilder res = new StringBuilder(); String fullClassName = getClass().getName(); String shortClassName = fullClassName.substring(fullClassName.lastIndexOf('.') + 1); res.append(shortClassName).append("{"); for (int i = 0; i < nRows; ++i) { if (i > 0) { res.append(","); } res.append("{"); for (int j = 0; j < nCols; ++j) { if (j > 0) { res.append(","); } res.append(getEntry(i, j)); } res.append("}"); } res.append("}"); return res.toString(); } /** * Returns true iff <code>object</code> is a * <code>RealMatrix</code> instance with the same dimensions as this * and all corresponding matrix entries are equal. * * @param object the object to test equality against. * @return true if object equals this */ @Override public boolean equals(final Object object) { if (object == this) { return true; } if (object instanceof RealMatrix == false) { return false; } RealMatrix m = (RealMatrix) object; final int nRows = getRowDimension(); final int nCols = getColumnDimension(); if (m.getColumnDimension() != nCols || m.getRowDimension() != nRows) { return false; } for (int row = 0; row < nRows; ++row) { for (int col = 0; col < nCols; ++col) { if (getEntry(row, col) != m.getEntry(row, col)) { return false; } } } return true; } /** * Computes a hashcode for the matrix. * * @return hashcode for matrix */ @Override public int hashCode() { int ret = 7; final int nRows = getRowDimension(); final int nCols = getColumnDimension(); ret = ret * 31 + nRows; ret = ret * 31 + nCols; for (int row = 0; row < nRows; ++row) { for (int col = 0; col < nCols; ++col) { ret = ret * 31 + (11 * (row + 1) + 17 * (col + 1)) * MathUtils.hash(getEntry(row, col)); } } return ret; } }