Example usage for org.apache.commons.math.linear MatrixUtils checkSubtractionCompatible

Introduction

In this page you can find the example usage for org.apache.commons.math.linear MatrixUtils checkSubtractionCompatible.

Prototype

public static void checkSubtractionCompatible(final AnyMatrix left, final AnyMatrix right)
        throws IllegalArgumentException 

Source Link

Document

Check if matrices are subtraction compatible

Usage

From source file:org.mitre.math.linear.BufferRealMatrix.java

/** {@inheritDoc} */
public BufferRealMatrix subtract(final BufferRealMatrix b) throws IllegalArgumentException {

    //        if (b == this) {
    //    return this.subtractSelf();
    // }/*from w  w  w .  j  a v  a 2 s  . c o  m*/
    // safety check
    MatrixUtils.checkSubtractionCompatible(this, b);

    try {
        final BufferRealMatrix c = new BufferRealMatrix(rows, columns, null);

        // perform addition block-wise, to ensure good cache behavior
        for (int blockIndex = 0; blockIndex < this.blockRows * this.blockColumns; ++blockIndex) {
            // all the same size, so should all be the same blockOffsets and layout
            final long blockOffset = this.getBlockOffset(blockIndex);
            DoubleBuffer adb = this.dataFileChannel
                    .map(FileChannel.MapMode.READ_WRITE, blockOffset, BLOCK_BYTE_SIZE).asDoubleBuffer();
            adb.clear();
            DoubleBuffer bdb = b.dataFileChannel
                    .map(FileChannel.MapMode.READ_WRITE, blockOffset, BLOCK_BYTE_SIZE).asDoubleBuffer();
            bdb.clear();
            DoubleBuffer cdb = c.dataFileChannel
                    .map(FileChannel.MapMode.READ_WRITE, blockOffset, BLOCK_BYTE_SIZE).asDoubleBuffer();
            cdb.clear();
            for (int k = 0; k < BLOCK_BYTE_SIZE / DOUBLE_BYTE_SIZE; k++) {
                try {
                    cdb.put(adb.get() - bdb.get());
                } catch (BufferUnderflowException e) {
                    LOG.fatal(String.format("BufferUnderflowException while adding elements at %d in block %d",
                            k, blockIndex));
                    throw e;
                }
            }
        }
        return c;
    } catch (IOException ioe) {
        throw new RuntimeException(ioe);
    }
}

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