diff --git a/src/java/org/apache/commons/math/linear/AbstractRealMatrix.java b/src/java/org/apache/commons/math/linear/AbstractRealMatrix.java
index 35025b617..980ae45e2 100644
--- a/src/java/org/apache/commons/math/linear/AbstractRealMatrix.java
+++ b/src/java/org/apache/commons/math/linear/AbstractRealMatrix.java
@@ -227,19 +227,7 @@ public abstract class AbstractRealMatrix implements RealMatrix, Serializable {
final int startColumn, final int endColumn)
throws MatrixIndexException {
- checkRowIndex(startRow);
- checkRowIndex(endRow);
- if (startRow > endRow) {
- throw new MatrixIndexException("initial row {0} after final row {1}",
- new Object[] { startRow, endRow });
- }
-
- checkColumnIndex(startColumn);
- checkColumnIndex(endColumn);
- if (startColumn > endColumn) {
- throw new MatrixIndexException("initial column {0} after final column {1}",
- new Object[] { startColumn, endColumn });
- }
+ checkSubMatrixIndex(startRow, endRow, startColumn, endColumn);
final RealMatrix subMatrix =
createMatrix(endRow - startRow + 1, endColumn - startColumn + 1);
@@ -257,29 +245,13 @@ public abstract class AbstractRealMatrix implements RealMatrix, Serializable {
public RealMatrix getSubMatrix(int[] selectedRows, int[] selectedColumns)
throws MatrixIndexException {
- if (selectedRows.length * selectedColumns.length == 0) {
- if (selectedRows.length == 0) {
- throw new MatrixIndexException("empty selected row index array", null);
- }
- throw new MatrixIndexException("empty selected column index array", null);
- }
+ checkSubMatrixIndex(selectedRows, selectedColumns);
final RealMatrix subMatrix =
createMatrix(selectedRows.length, selectedColumns.length);
- try {
- for (int i = 0; i < selectedRows.length; i++) {
- for (int j = 0; j < selectedColumns.length; j++) {
- subMatrix.setEntry(i, j, getEntry(selectedRows[i], selectedColumns[j]));
- }
- }
- } catch (ArrayIndexOutOfBoundsException e) {
- // we redo the loop with checks enabled
- // in order to generate an appropriate message
- for (final int row : selectedRows) {
- checkRowIndex(row);
- }
- for (final int column : selectedColumns) {
- checkColumnIndex(column);
+ for (int i = 0; i < selectedRows.length; i++) {
+ for (int j = 0; j < selectedColumns.length; j++) {
+ subMatrix.setEntry(i, j, getEntry(selectedRows[i], selectedColumns[j]));
}
}
@@ -525,6 +497,14 @@ public abstract class AbstractRealMatrix implements RealMatrix, Serializable {
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() {
@@ -858,6 +838,59 @@ public abstract class AbstractRealMatrix implements RealMatrix, Serializable {
}
}
+ /**
+ * Check if submatrix ranges indices are valid.
+ * Rows and columns are indicated counting from 0 to n-1.
+ *
+ * @param startRow Initial row index
+ * @param endRow Final row index
+ * @param startColumn Initial column index
+ * @param endColumn Final column index
+ * @exception MatrixIndexException if the indices are not valid
+ */
+ protected void checkSubMatrixIndex(final int startRow, final int endRow,
+ final int startColumn, final int endColumn) {
+ checkRowIndex(startRow);
+ checkRowIndex(endRow);
+ if (startRow > endRow) {
+ throw new MatrixIndexException("initial row {0} after final row {1}",
+ new Object[] { startRow, endRow });
+ }
+
+ checkColumnIndex(startColumn);
+ checkColumnIndex(endColumn);
+ if (startColumn > endColumn) {
+ throw new MatrixIndexException("initial column {0} after final column {1}",
+ new Object[] { startColumn, endColumn });
+ }
+
+
+ }
+
+ /**
+ * Check if submatrix ranges indices are valid.
+ * Rows and columns are indicated counting from 0 to n-1.
+ *
+ * @param selectedRows Array of row indices.
+ * @param selectedColumns Array of column indices.
+ * @exception MatrixIndexException if row or column selections are not valid
+ */
+ protected void checkSubMatrixIndex(final int[] selectedRows, final int[] selectedColumns) {
+ if (selectedRows.length * selectedColumns.length == 0) {
+ if (selectedRows.length == 0) {
+ throw new MatrixIndexException("empty selected row index array", null);
+ }
+ throw new MatrixIndexException("empty selected column index array", null);
+ }
+
+ for (final int row : selectedRows) {
+ checkRowIndex(row);
+ }
+ for (final int column : selectedColumns) {
+ checkColumnIndex(column);
+ }
+ }
+
/**
* Check if a matrix is addition compatible with the instance
* @param m matrix to check
diff --git a/src/java/org/apache/commons/math/linear/RealMatrix.java b/src/java/org/apache/commons/math/linear/RealMatrix.java
index 91ca3936c..a954bccc4 100644
--- a/src/java/org/apache/commons/math/linear/RealMatrix.java
+++ b/src/java/org/apache/commons/math/linear/RealMatrix.java
@@ -359,6 +359,42 @@ public interface RealMatrix {
*/
void setEntry(int row, int column, double value) throws MatrixIndexException;
+ /**
+ * Change an entry in the specified row and column.
+ *
+ * Row and column indices start at 0 and must satisfy
+ *
+ * 0 <= row < rowDimension 0 <= column < columnDimension
+ * otherwise a MatrixIndexException is thrown.
+ *
+ * @param row row location of entry to be set
+ * @param column column location of entry to be set
+ * @param increment value to add to the current matrix entry in row,column
+ * @throws MatrixIndexException if the row or column index is not valid
+ * @since 2.0
+ */
+ void addToEntry(int row, int column, double increment) throws MatrixIndexException;
+
+ /**
+ * Change an entry in the specified row and column.
+ *
+ * Row and column indices start at 0 and must satisfy
+ *
+ * 0 <= row < rowDimension 0 <= column < columnDimension
+ * otherwise a MatrixIndexException is thrown.
+ *
+ * @param row row location of entry to be set
+ * @param column column location of entry to be set
+ * @param factor multiplication factor for the current matrix entry in row,column
+ * @throws MatrixIndexException if the row or column index is not valid
+ * @since 2.0
+ */
+ void multiplyEntry(int row, int column, double factor) throws MatrixIndexException;
+
/**
* Returns the transpose of this matrix.
*
diff --git a/src/java/org/apache/commons/math/linear/RealMatrixImpl.java b/src/java/org/apache/commons/math/linear/RealMatrixImpl.java
index 7e5a6d515..830d97939 100644
--- a/src/java/org/apache/commons/math/linear/RealMatrixImpl.java
+++ b/src/java/org/apache/commons/math/linear/RealMatrixImpl.java
@@ -370,6 +370,34 @@ public class RealMatrixImpl extends AbstractRealMatrix implements Serializable {
}
}
+ /** {@inheritDoc} */
+ public void addToEntry(final int row, final int column, final double increment)
+ throws MatrixIndexException {
+ try {
+ data[row][column] += increment;
+ } catch (ArrayIndexOutOfBoundsException e) {
+ throw new MatrixIndexException("no entry at indices ({0}, {1}) in a {2}x{3} matrix",
+ new Object[] {
+ row, column,
+ getRowDimension(), getColumnDimension()
+ });
+ }
+ }
+
+ /** {@inheritDoc} */
+ public void multiplyEntry(final int row, final int column, final double factor)
+ throws MatrixIndexException {
+ try {
+ data[row][column] *= factor;
+ } catch (ArrayIndexOutOfBoundsException e) {
+ throw new MatrixIndexException("no entry at indices ({0}, {1}) in a {2}x{3} matrix",
+ new Object[] {
+ row, column,
+ getRowDimension(), getColumnDimension()
+ });
+ }
+ }
+
/** {@inheritDoc} */
public int getRowDimension() {
return (data == null) ? 0 : data.length;
diff --git a/src/test/org/apache/commons/math/linear/RealMatrixImplTest.java b/src/test/org/apache/commons/math/linear/RealMatrixImplTest.java
index 3a50ab946..fa2d3156e 100644
--- a/src/test/org/apache/commons/math/linear/RealMatrixImplTest.java
+++ b/src/test/org/apache/commons/math/linear/RealMatrixImplTest.java
@@ -746,14 +746,6 @@ public final class RealMatrixImplTest extends TestCase {
(new double[][] {{3.0,4.0,5.0},{4.0,7.0,5.0},{3.0,2.0,10.0}});
assertEquals(expected, m);
- // javadoc example
- RealMatrixImpl matrix = (RealMatrixImpl) MatrixUtils.createRealMatrix
- (new double[][] {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 0, 1 , 2}});
- matrix.setSubMatrix(new double[][] {{3, 4}, {5, 6}}, 1, 1);
- expected = MatrixUtils.createRealMatrix
- (new double[][] {{1, 2, 3, 4}, {5, 3, 4, 8}, {9, 5 ,6, 2}});
- assertEquals(expected, matrix);
-
// dimension overflow
try {
m.setSubMatrix(testData,1,1);