1/*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements.  See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License.  You may obtain a copy of the License at
8 *
9 *      http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18package org.apache.commons.math.linear;
19
20import java.io.Serializable;
21
22import org.apache.commons.math.Field;
23import org.apache.commons.math.FieldElement;
24import org.apache.commons.math.MathRuntimeException;
25import org.apache.commons.math.linear.MatrixVisitorException;
26import org.apache.commons.math.exception.util.LocalizedFormats;
27
28/**
29 * Implementation of FieldMatrix<T> using a {@link FieldElement}[][] array to store entries.
30 * <p>
31 * As specified in the {@link FieldMatrix} interface, matrix element indexing
32 * is 0-based -- e.g., <code>getEntry(0, 0)</code>
33 * returns the element in the first row, first column of the matrix.</li></ul>
34 * </p>
35 *
36 * @param <T> the type of the field elements
37 * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 févr. 2011) $
38 */
39public class Array2DRowFieldMatrix<T extends FieldElement<T>> extends AbstractFieldMatrix<T> implements Serializable {
40
41    /** Serializable version identifier */
42    private static final long serialVersionUID = 7260756672015356458L;
43
44    /** Entries of the matrix */
45    protected T[][] data;
46
47    /**
48     * Creates a matrix with no data
49     * @param field field to which the elements belong
50     */
51    public Array2DRowFieldMatrix(final Field<T> field) {
52        super(field);
53    }
54
55    /**
56     * Create a new FieldMatrix<T> with the supplied row and column dimensions.
57     *
58     * @param field field to which the elements belong
59     * @param rowDimension  the number of rows in the new matrix
60     * @param columnDimension  the number of columns in the new matrix
61     * @throws IllegalArgumentException if row or column dimension is not
62     *  positive
63     */
64    public Array2DRowFieldMatrix(final Field<T> field,
65                           final int rowDimension, final int columnDimension)
66        throws IllegalArgumentException {
67        super(field, rowDimension, columnDimension);
68        data = buildArray(field, rowDimension, columnDimension);
69    }
70
71    /**
72     * Create a new FieldMatrix<T> using the input array as the underlying
73     * data array.
74     * <p>The input array is copied, not referenced. This constructor has
75     * the same effect as calling {@link #Array2DRowFieldMatrix(FieldElement[][], boolean)}
76     * with the second argument set to <code>true</code>.</p>
77     *
78     * @param d data for new matrix
79     * @throws IllegalArgumentException if <code>d</code> is not rectangular
80     *  (not all rows have the same length) or empty
81     * @throws NullPointerException if <code>d</code> is null
82     * @see #Array2DRowFieldMatrix(FieldElement[][], boolean)
83     */
84    public Array2DRowFieldMatrix(final T[][] d)
85        throws IllegalArgumentException, NullPointerException {
86        super(extractField(d));
87        copyIn(d);
88    }
89
90    /**
91     * Create a new FieldMatrix<T> using the input array as the underlying
92     * data array.
93     * <p>If an array is built specially in order to be embedded in a
94     * FieldMatrix<T> and not used directly, the <code>copyArray</code> may be
95     * set to <code>false</code. This will prevent the copying and improve
96     * performance as no new array will be built and no data will be copied.</p>
97     * @param d data for new matrix
98     * @param copyArray if true, the input array will be copied, otherwise
99     * it will be referenced
100     * @throws IllegalArgumentException if <code>d</code> is not rectangular
101     *  (not all rows have the same length) or empty
102     * @throws NullPointerException if <code>d</code> is null
103     * @see #Array2DRowFieldMatrix(FieldElement[][])
104     */
105    public Array2DRowFieldMatrix(final T[][] d, final boolean copyArray)
106        throws IllegalArgumentException, NullPointerException {
107        super(extractField(d));
108        if (copyArray) {
109            copyIn(d);
110        } else {
111            if (d == null) {
112                throw new NullPointerException();
113            }
114            final int nRows = d.length;
115            if (nRows == 0) {
116                throw MathRuntimeException.createIllegalArgumentException(
117                      LocalizedFormats.AT_LEAST_ONE_ROW);
118            }
119            final int nCols = d[0].length;
120            if (nCols == 0) {
121                throw MathRuntimeException.createIllegalArgumentException(
122                      LocalizedFormats.AT_LEAST_ONE_COLUMN);
123            }
124            for (int r = 1; r < nRows; r++) {
125                if (d[r].length != nCols) {
126                    throw MathRuntimeException.createIllegalArgumentException(
127                          LocalizedFormats.DIFFERENT_ROWS_LENGTHS, nCols, d[r].length);
128                }
129            }
130            data = d;
131        }
132    }
133
134    /**
135     * Create a new (column) FieldMatrix<T> using <code>v</code> as the
136     * data for the unique column of the <code>v.length x 1</code> matrix
137     * created.
138     * <p>The input array is copied, not referenced.</p>
139     *
140     * @param v column vector holding data for new matrix
141     */
142    public Array2DRowFieldMatrix(final T[] v) {
143        super(extractField(v));
144        final int nRows = v.length;
145        data = buildArray(getField(), nRows, 1);
146        for (int row = 0; row < nRows; row++) {
147            data[row][0] = v[row];
148        }
149    }
150
151    /** {@inheritDoc} */
152    @Override
153    public FieldMatrix<T> createMatrix(final int rowDimension, final int columnDimension)
154        throws IllegalArgumentException {
155        return new Array2DRowFieldMatrix<T>(getField(), rowDimension, columnDimension);
156    }
157
158    /** {@inheritDoc} */
159    @Override
160    public FieldMatrix<T> copy() {
161        return new Array2DRowFieldMatrix<T>(copyOut(), false);
162    }
163
164    /** {@inheritDoc} */
165    @Override
166    public FieldMatrix<T> add(final FieldMatrix<T> m)
167        throws IllegalArgumentException {
168        try {
169            return add((Array2DRowFieldMatrix<T>) m);
170        } catch (ClassCastException cce) {
171            return super.add(m);
172        }
173    }
174
175    /**
176     * Compute the sum of this and <code>m</code>.
177     *
178     * @param m    matrix to be added
179     * @return     this + m
180     * @throws  IllegalArgumentException if m is not the same size as this
181     */
182    public Array2DRowFieldMatrix<T> add(final Array2DRowFieldMatrix<T> m)
183        throws IllegalArgumentException {
184
185        // safety check
186        checkAdditionCompatible(m);
187
188        final int rowCount    = getRowDimension();
189        final int columnCount = getColumnDimension();
190        final T[][] outData = buildArray(getField(), rowCount, columnCount);
191        for (int row = 0; row < rowCount; row++) {
192            final T[] dataRow    = data[row];
193            final T[] mRow       = m.data[row];
194            final T[] outDataRow = outData[row];
195            for (int col = 0; col < columnCount; col++) {
196                outDataRow[col] = dataRow[col].add(mRow[col]);
197            }
198        }
199
200        return new Array2DRowFieldMatrix<T>(outData, false);
201
202    }
203
204    /** {@inheritDoc} */
205    @Override
206    public FieldMatrix<T> subtract(final FieldMatrix<T> m)
207        throws IllegalArgumentException {
208        try {
209            return subtract((Array2DRowFieldMatrix<T>) m);
210        } catch (ClassCastException cce) {
211            return super.subtract(m);
212        }
213    }
214
215    /**
216     * Compute  this minus <code>m</code>.
217     *
218     * @param m    matrix to be subtracted
219     * @return     this + m
220     * @throws  IllegalArgumentException if m is not the same size as this
221     */
222    public Array2DRowFieldMatrix<T> subtract(final Array2DRowFieldMatrix<T> m)
223        throws IllegalArgumentException {
224
225        // safety check
226        checkSubtractionCompatible(m);
227
228        final int rowCount    = getRowDimension();
229        final int columnCount = getColumnDimension();
230        final T[][] outData = buildArray(getField(), rowCount, columnCount);
231        for (int row = 0; row < rowCount; row++) {
232            final T[] dataRow    = data[row];
233            final T[] mRow       = m.data[row];
234            final T[] outDataRow = outData[row];
235            for (int col = 0; col < columnCount; col++) {
236                outDataRow[col] = dataRow[col].subtract(mRow[col]);
237            }
238        }
239
240        return new Array2DRowFieldMatrix<T>(outData, false);
241
242    }
243
244    /** {@inheritDoc} */
245    @Override
246    public FieldMatrix<T> multiply(final FieldMatrix<T> m)
247        throws IllegalArgumentException {
248        try {
249            return multiply((Array2DRowFieldMatrix<T>) m);
250        } catch (ClassCastException cce) {
251            return super.multiply(m);
252        }
253    }
254
255    /**
256     * Returns the result of postmultiplying this by <code>m</code>.
257     * @param m    matrix to postmultiply by
258     * @return     this*m
259     * @throws     IllegalArgumentException
260     *             if columnDimension(this) != rowDimension(m)
261     */
262    public Array2DRowFieldMatrix<T> multiply(final Array2DRowFieldMatrix<T> m)
263        throws IllegalArgumentException {
264
265        // safety check
266        checkMultiplicationCompatible(m);
267
268        final int nRows = this.getRowDimension();
269        final int nCols = m.getColumnDimension();
270        final int nSum = this.getColumnDimension();
271        final T[][] outData = buildArray(getField(), nRows, nCols);
272        for (int row = 0; row < nRows; row++) {
273            final T[] dataRow    = data[row];
274            final T[] outDataRow = outData[row];
275            for (int col = 0; col < nCols; col++) {
276                T sum = getField().getZero();
277                for (int i = 0; i < nSum; i++) {
278                    sum = sum.add(dataRow[i].multiply(m.data[i][col]));
279                }
280                outDataRow[col] = sum;
281            }
282        }
283
284        return new Array2DRowFieldMatrix<T>(outData, false);
285
286    }
287
288    /** {@inheritDoc} */
289    @Override
290    public T[][] getData() {
291        return copyOut();
292    }
293
294    /**
295     * Returns a reference to the underlying data array.
296     * <p>
297     * Does <strong>not</strong> make a fresh copy of the underlying data.</p>
298     *
299     * @return 2-dimensional array of entries
300     */
301    public T[][] getDataRef() {
302        return data;
303    }
304
305    /** {@inheritDoc} */
306    @Override
307    public void setSubMatrix(final T[][] subMatrix, final int row, final int column)
308    throws MatrixIndexException {
309        if (data == null) {
310            if (row > 0) {
311                throw MathRuntimeException.createIllegalStateException(
312                      LocalizedFormats.FIRST_ROWS_NOT_INITIALIZED_YET, row);
313            }
314            if (column > 0) {
315                throw MathRuntimeException.createIllegalStateException(
316                      LocalizedFormats.FIRST_COLUMNS_NOT_INITIALIZED_YET, column);
317            }
318            final int nRows = subMatrix.length;
319            if (nRows == 0) {
320                throw MathRuntimeException.createIllegalArgumentException(
321                      LocalizedFormats.AT_LEAST_ONE_ROW);
322            }
323
324            final int nCols = subMatrix[0].length;
325            if (nCols == 0) {
326                throw MathRuntimeException.createIllegalArgumentException(
327                      LocalizedFormats.AT_LEAST_ONE_COLUMN);
328            }
329            data = buildArray(getField(), subMatrix.length, nCols);
330            for (int i = 0; i < data.length; ++i) {
331                if (subMatrix[i].length != nCols) {
332                    throw MathRuntimeException.createIllegalArgumentException(
333                          LocalizedFormats.DIFFERENT_ROWS_LENGTHS, nCols, subMatrix[i].length);
334                }
335                System.arraycopy(subMatrix[i], 0, data[i + row], column, nCols);
336            }
337        } else {
338            super.setSubMatrix(subMatrix, row, column);
339        }
340
341    }
342
343    /** {@inheritDoc} */
344    @Override
345    public T getEntry(final int row, final int column)
346        throws MatrixIndexException {
347        try {
348            return data[row][column];
349        } catch (ArrayIndexOutOfBoundsException e) {
350            throw new MatrixIndexException(
351                      LocalizedFormats.NO_SUCH_MATRIX_ENTRY, row, column, getRowDimension(), getColumnDimension());
352        }
353    }
354
355    /** {@inheritDoc} */
356    @Override
357    public void setEntry(final int row, final int column, final T value)
358        throws MatrixIndexException {
359        try {
360            data[row][column] = value;
361        } catch (ArrayIndexOutOfBoundsException e) {
362            throw new MatrixIndexException(
363                      LocalizedFormats.NO_SUCH_MATRIX_ENTRY, row, column, getRowDimension(), getColumnDimension());
364        }
365    }
366
367    /** {@inheritDoc} */
368    @Override
369    public void addToEntry(final int row, final int column, final T increment)
370        throws MatrixIndexException {
371        try {
372            data[row][column] = data[row][column].add(increment);
373        } catch (ArrayIndexOutOfBoundsException e) {
374            throw new MatrixIndexException(
375                      LocalizedFormats.NO_SUCH_MATRIX_ENTRY, row, column, getRowDimension(), getColumnDimension());
376        }
377    }
378
379    /** {@inheritDoc} */
380    @Override
381    public void multiplyEntry(final int row, final int column, final T factor)
382        throws MatrixIndexException {
383        try {
384            data[row][column] = data[row][column].multiply(factor);
385        } catch (ArrayIndexOutOfBoundsException e) {
386            throw new MatrixIndexException(
387                      LocalizedFormats.NO_SUCH_MATRIX_ENTRY, row, column, getRowDimension(), getColumnDimension());
388        }
389    }
390
391    /** {@inheritDoc} */
392    @Override
393    public int getRowDimension() {
394        return (data == null) ? 0 : data.length;
395    }
396
397    /** {@inheritDoc} */
398    @Override
399    public int getColumnDimension() {
400        return ((data == null) || (data[0] == null)) ? 0 : data[0].length;
401    }
402
403    /** {@inheritDoc} */
404    @Override
405    public T[] operate(final T[] v)
406        throws IllegalArgumentException {
407        final int nRows = this.getRowDimension();
408        final int nCols = this.getColumnDimension();
409        if (v.length != nCols) {
410            throw MathRuntimeException.createIllegalArgumentException(
411                  LocalizedFormats.VECTOR_LENGTH_MISMATCH, v.length, nCols);
412        }
413        final T[] out = buildArray(getField(), nRows);
414        for (int row = 0; row < nRows; row++) {
415            final T[] dataRow = data[row];
416            T sum = getField().getZero();
417            for (int i = 0; i < nCols; i++) {
418                sum = sum.add(dataRow[i].multiply(v[i]));
419            }
420            out[row] = sum;
421        }
422        return out;
423    }
424
425    /** {@inheritDoc} */
426    @Override
427    public T[] preMultiply(final T[] v)
428        throws IllegalArgumentException {
429
430        final int nRows = getRowDimension();
431        final int nCols = getColumnDimension();
432        if (v.length != nRows) {
433            throw MathRuntimeException.createIllegalArgumentException(
434                  LocalizedFormats.VECTOR_LENGTH_MISMATCH, v.length, nRows);
435        }
436
437        final T[] out = buildArray(getField(), nCols);
438        for (int col = 0; col < nCols; ++col) {
439            T sum = getField().getZero();
440            for (int i = 0; i < nRows; ++i) {
441                sum = sum.add(data[i][col].multiply(v[i]));
442            }
443            out[col] = sum;
444        }
445
446        return out;
447
448    }
449
450    /** {@inheritDoc} */
451    @Override
452    public T walkInRowOrder(final FieldMatrixChangingVisitor<T> visitor)
453        throws MatrixVisitorException {
454        final int rows    = getRowDimension();
455        final int columns = getColumnDimension();
456        visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
457        for (int i = 0; i < rows; ++i) {
458            final T[] rowI = data[i];
459            for (int j = 0; j < columns; ++j) {
460                rowI[j] = visitor.visit(i, j, rowI[j]);
461            }
462        }
463        return visitor.end();
464    }
465
466    /** {@inheritDoc} */
467    @Override
468    public T walkInRowOrder(final FieldMatrixPreservingVisitor<T> visitor)
469        throws MatrixVisitorException {
470        final int rows    = getRowDimension();
471        final int columns = getColumnDimension();
472        visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
473        for (int i = 0; i < rows; ++i) {
474            final T[] rowI = data[i];
475            for (int j = 0; j < columns; ++j) {
476                visitor.visit(i, j, rowI[j]);
477            }
478        }
479        return visitor.end();
480    }
481
482    /** {@inheritDoc} */
483    @Override
484    public T walkInRowOrder(final FieldMatrixChangingVisitor<T> visitor,
485                            final int startRow, final int endRow,
486                            final int startColumn, final int endColumn)
487        throws MatrixIndexException, MatrixVisitorException {
488        checkSubMatrixIndex(startRow, endRow, startColumn, endColumn);
489        visitor.start(getRowDimension(), getColumnDimension(),
490                      startRow, endRow, startColumn, endColumn);
491        for (int i = startRow; i <= endRow; ++i) {
492            final T[] rowI = data[i];
493            for (int j = startColumn; j <= endColumn; ++j) {
494                rowI[j] = visitor.visit(i, j, rowI[j]);
495            }
496        }
497        return visitor.end();
498    }
499
500    /** {@inheritDoc} */
501    @Override
502    public T walkInRowOrder(final FieldMatrixPreservingVisitor<T> visitor,
503                            final int startRow, final int endRow,
504                            final int startColumn, final int endColumn)
505        throws MatrixIndexException, MatrixVisitorException {
506        checkSubMatrixIndex(startRow, endRow, startColumn, endColumn);
507        visitor.start(getRowDimension(), getColumnDimension(),
508                      startRow, endRow, startColumn, endColumn);
509        for (int i = startRow; i <= endRow; ++i) {
510            final T[] rowI = data[i];
511            for (int j = startColumn; j <= endColumn; ++j) {
512                visitor.visit(i, j, rowI[j]);
513            }
514        }
515        return visitor.end();
516    }
517
518    /** {@inheritDoc} */
519    @Override
520    public T walkInColumnOrder(final FieldMatrixChangingVisitor<T> visitor)
521        throws MatrixVisitorException {
522        final int rows    = getRowDimension();
523        final int columns = getColumnDimension();
524        visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
525        for (int j = 0; j < columns; ++j) {
526            for (int i = 0; i < rows; ++i) {
527                final T[] rowI = data[i];
528                rowI[j] = visitor.visit(i, j, rowI[j]);
529            }
530        }
531        return visitor.end();
532    }
533
534    /** {@inheritDoc} */
535    @Override
536    public T walkInColumnOrder(final FieldMatrixPreservingVisitor<T> visitor)
537        throws MatrixVisitorException {
538        final int rows    = getRowDimension();
539        final int columns = getColumnDimension();
540        visitor.start(rows, columns, 0, rows - 1, 0, columns - 1);
541        for (int j = 0; j < columns; ++j) {
542            for (int i = 0; i < rows; ++i) {
543                visitor.visit(i, j, data[i][j]);
544            }
545        }
546        return visitor.end();
547    }
548
549    /** {@inheritDoc} */
550    @Override
551    public T walkInColumnOrder(final FieldMatrixChangingVisitor<T> visitor,
552                               final int startRow, final int endRow,
553                               final int startColumn, final int endColumn)
554        throws MatrixIndexException, MatrixVisitorException {
555        checkSubMatrixIndex(startRow, endRow, startColumn, endColumn);
556        visitor.start(getRowDimension(), getColumnDimension(),
557                      startRow, endRow, startColumn, endColumn);
558        for (int j = startColumn; j <= endColumn; ++j) {
559            for (int i = startRow; i <= endRow; ++i) {
560                final T[] rowI = data[i];
561                rowI[j] = visitor.visit(i, j, rowI[j]);
562            }
563        }
564        return visitor.end();
565    }
566
567    /** {@inheritDoc} */
568    @Override
569    public T walkInColumnOrder(final FieldMatrixPreservingVisitor<T> visitor,
570                               final int startRow, final int endRow,
571                               final int startColumn, final int endColumn)
572        throws MatrixIndexException, MatrixVisitorException {
573        checkSubMatrixIndex(startRow, endRow, startColumn, endColumn);
574        visitor.start(getRowDimension(), getColumnDimension(),
575                      startRow, endRow, startColumn, endColumn);
576        for (int j = startColumn; j <= endColumn; ++j) {
577            for (int i = startRow; i <= endRow; ++i) {
578                visitor.visit(i, j, data[i][j]);
579            }
580        }
581        return visitor.end();
582    }
583
584    /**
585     * Returns a fresh copy of the underlying data array.
586     *
587     * @return a copy of the underlying data array.
588     */
589    private T[][] copyOut() {
590        final int nRows = this.getRowDimension();
591        final T[][] out = buildArray(getField(), nRows, getColumnDimension());
592        // can't copy 2-d array in one shot, otherwise get row references
593        for (int i = 0; i < nRows; i++) {
594            System.arraycopy(data[i], 0, out[i], 0, data[i].length);
595        }
596        return out;
597    }
598
599    /**
600     * Replaces data with a fresh copy of the input array.
601     * <p>
602     * Verifies that the input array is rectangular and non-empty.</p>
603     *
604     * @param in data to copy in
605     * @throws IllegalArgumentException if input array is empty or not
606     *    rectangular
607     * @throws NullPointerException if input array is null
608     */
609    private void copyIn(final T[][] in) {
610        setSubMatrix(in, 0, 0);
611    }
612
613}
614