/* file: */
* Copyright 2014-2019 Intel Corporation.
* This software and the related documents are Intel copyrighted  materials,  and
* your use of  them is  governed by the  express license  under which  they were
* provided to you (License).  Unless the License provides otherwise, you may not
* use, modify, copy, publish, distribute,  disclose or transmit this software or
* the related documents without Intel's prior written permission.
* This software and the related documents  are provided as  is,  with no express
* or implied  warranties,  other  than those  that are  expressly stated  in the
* License.

 //  Content:
 //     Java example of using matrix data structures


import java.nio.DoubleBuffer;


class DataStructuresMatrix {
    private static final int nVectorsMatrix  = 10;
    private static final int nFeaturesMatrix = 11;
    private static final int firstReadRow     = 0;
    private static final int nRead            = 5;

    private static DaalContext context = new DaalContext();

    public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
        System.out.println("Matrix numeric table example\n");
        int readFeatureIdx;

        double[] data = {
            0.0f, 0.1f, 0.2f, 0.3f, 0.4f, 0.5f, 0.6f, 0.7f, 0.8f, 0.9f, 1,
            1.0f, 1.1f, 1.2f, 1.3f, 1.4f, 1.5f, 1.6f, 1.7f, 1.8f, 1.9f, 2,
            2.0f, 2.1f, 2.2f, 2.3f, 2.4f, 2.5f, 2.6f, 2.7f, 2.8f, 2.9f, 3,
            3.0f, 3.1f, 3.2f, 3.3f, 3.4f, 3.5f, 3.6f, 3.7f, 3.8f, 3.9f, 4,
            4.0f, 4.1f, 4.2f, 4.3f, 4.4f, 4.5f, 4.6f, 4.7f, 4.8f, 4.9f, 5,
            5.0f, 5.1f, 5.2f, 5.3f, 5.4f, 5.5f, 5.6f, 5.7f, 5.8f, 5.9f, 1,
            6.0f, 6.1f, 6.2f, 6.3f, 6.4f, 6.5f, 6.6f, 6.7f, 6.8f, 6.9f, 2,
            7.0f, 7.1f, 7.2f, 7.3f, 7.4f, 7.5f, 7.6f, 7.7f, 7.8f, 7.9f, 3,
            8.0f, 8.1f, 8.2f, 8.3f, 8.4f, 8.5f, 8.6f, 8.7f, 8.8f, 8.9f, 4,
            9.0f, 9.1f, 9.2f, 9.3f, 9.4f, 9.5f, 9.6f, 9.7f, 9.8f, 9.9f, 5

        Matrix dataTable = new Matrix(context, data, nFeaturesMatrix, nVectorsMatrix);

        /* Read a block of rows */
        DoubleBuffer dataDouble = DoubleBuffer.allocate(nRead * nFeaturesMatrix);

        dataDouble = dataTable.getBlockOfRows(firstReadRow, nRead, dataDouble);
        System.out.printf("%d  rows are read\n", nRead);
        printDoubleBuffer(dataDouble, nFeaturesMatrix, nRead, "Print 5 rows from matrix data array as float:");
        dataTable.releaseBlockOfRows(firstReadRow, nRead, dataDouble);

        readFeatureIdx = 2;

        /* Set new values in Matrix */
        dataTable.set(firstReadRow, readFeatureIdx, (double)-1);
        dataTable.set(firstReadRow + 1, readFeatureIdx, (double)-2);
        dataTable.set(firstReadRow + 2, readFeatureIdx, (double)-3);

        /* Read a feature (column) */
        DoubleBuffer dataDoubleFeatures = DoubleBuffer.allocate((int) nVectorsMatrix);
        dataDoubleFeatures = dataTable.getBlockOfColumnValues(readFeatureIdx, firstReadRow, nVectorsMatrix, dataDoubleFeatures);
        printDoubleBuffer(dataDoubleFeatures, 1, nVectorsMatrix, "Print the third feature of matrix data:");
        dataTable.releaseBlockOfColumnValues(readFeatureIdx, firstReadRow, nVectorsMatrix, dataDoubleFeatures);


    private static void printDoubleBuffer(DoubleBuffer buf, long nColumns, long nRows, String message) {
        int step = (int) nColumns;
        for (int i = 0; i < nRows; i++) {
            for (int j = 0; j < nColumns; j++) {
                System.out.format("%6.3f   ", buf.get(i * step + j));
For more complete information about compiler optimizations, see our Optimization Notice.
Select sticky button color: 
Orange (only for download buttons)