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added a static method createBlocksLayout to prepare array before constructing the matrix 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@730838 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Luc Maisonobe 2009-01-02 20:21:09 +00:00
parent da54a21c78
commit dc68d63d33
1 changed files with 38 additions and 8 deletions
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46
src/java/org/apache/commons/math/linear/DenseRealMatrix.java
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@ -104,14 +104,7 @@ public class DenseRealMatrix extends AbstractRealMatrix implements Serializable
blockColumns = (columns + BLOCK_SIZE - 1) / BLOCK_SIZE;
// allocate storage blocks, taking care of smaller ones at right and bottom
blocks = new double[blockRows * blockColumns][];
int blockIndex = 0;
for (int iBlock = 0; iBlock < blockRows; ++iBlock) {
final int iHeight = blockHeight(iBlock);
for (int jBlock = 0; jBlock < blockColumns; ++jBlock) {
blocks[blockIndex++] = new double[iHeight * blockWidth(jBlock)];
}
}
blocks = createBlocksLayout(rows, columns);
}
@ -144,6 +137,7 @@ public class DenseRealMatrix extends AbstractRealMatrix implements Serializable
*
* @exception IllegalArgumentException if <code>blockData</code> shape is
* inconsistent with block layout
* @see #createBlocksLayout(int, int)
* @see #toBlocksLayout(double[][])
* @see #DenseRealMatrix(double[][])
*/
@ -205,6 +199,7 @@ public class DenseRealMatrix extends AbstractRealMatrix implements Serializable
* @return a new data array containing the same entries but in blocks layout
* @exception IllegalArgumentException if <code>rawData</code> is not rectangular
* (not all rows have the same length)
* @see #createBlocksLayout(int, int)
* @see #DenseRealMatrix(int, int, double[][], boolean)
*/
public static double[][] toBlocksLayout(final double[][] rawData)
@ -252,6 +247,41 @@ public class DenseRealMatrix extends AbstractRealMatrix implements Serializable
}
/**
* Create a data array in blocks layout.
* <p>
* This method can be used to create the array argument of the {@link
* DenseRealMatrix#DenseRealMatrix(int, int, double[][], boolean)} constructor.
* </p>
* @param rows the number of rows in the new matrix
* @param columns the number of columns in the new matrix
* @return a new data array in blocks layout
* @see #toBlocksLayout(double[][])
* @see #DenseRealMatrix(int, int, double[][], boolean)
*/
public static double[][] createBlocksLayout(final int rows, final int columns)
throws IllegalArgumentException {
final int blockRows = (rows + BLOCK_SIZE - 1) / BLOCK_SIZE;
final int blockColumns = (columns + BLOCK_SIZE - 1) / BLOCK_SIZE;
final double[][] blocks = new double[blockRows * blockColumns][];
for (int iBlock = 0, blockIndex = 0; iBlock < blockRows; ++iBlock) {
final int pStart = iBlock * BLOCK_SIZE;
final int pEnd = Math.min(pStart + BLOCK_SIZE, rows);
final int iHeight = pEnd - pStart;
for (int jBlock = 0; jBlock < blockColumns; ++jBlock, ++blockIndex) {
final int qStart = jBlock * BLOCK_SIZE;
final int qEnd = Math.min(qStart + BLOCK_SIZE, columns);
final int jWidth = qEnd - qStart;
blocks[blockIndex] = new double[iHeight * jWidth];
}
}
return blocks;
}
/** {@inheritDoc} */
public RealMatrix createMatrix(final int rowDimension, final int columnDimension)
throws IllegalArgumentException {