Here you can find the source of toDoubleArray(byte[] data)
| Parameter | Description |
|---|---|
| data | a parameter |
public static double[] toDoubleArray(byte[] data)
//package com.java2s; /*// ww w . ja v a 2s.c o m * This file is part of the LIRe project: http://www.semanticmetadata.net/lire * LIRe is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * LIRe is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with LIRe; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * We kindly ask you to refer the following paper in any publication mentioning Lire: * * Lux Mathias, Savvas A. Chatzichristofis. Lire: Lucene Image Retrieval ? * An Extensible Java CBIR Library. In proceedings of the 16th ACM International * Conference on Multimedia, pp. 1085-1088, Vancouver, Canada, 2008 * * http://doi.acm.org/10.1145/1459359.1459577 * * Copyright statement: * -------------------- * (c) 2002-2011 by Mathias Lux (mathias@juggle.at) * http://www.semanticmetadata.net/lire */ public class Main { /** * Convenience method for creating a double array from a byte array. * * @param data * @return */ public static double[] toDoubleArray(byte[] data) { double[] result = new double[data.length / 8]; byte[] tmp = new byte[8]; for (int i = 0; i < result.length; i++) { System.arraycopy(data, i * 8, tmp, 0, 8); result[i] = toDouble(tmp); } return result; } /** * Convenience method for creating a double array from a byte array. * * @param data * @param length * @param offset * @return */ public static double[] toDoubleArray(byte[] data, int offset, int length) { double[] result = new double[length / 8]; byte[] tmp = new byte[8]; for (int i = offset; i < length / 8; i++) { System.arraycopy(data, (i - offset) * 8 + offset, tmp, 0, 8); result[i] = toDouble(tmp); } return result; } public static double[] toDoubleArray(float[] d) { double[] result = new double[d.length]; for (int i = 0; i < result.length; i++) { result[i] = (double) d[i]; } return result; } /** * Converts a byte array with 4 elements to a double. Used to put doubles into a byte[] payload in a convenient * and fast way by shifting without using streams (which is kind of slow). Use * {@link net.semanticmetadata.lire.utils.SerializationUtils#toBytes(double)} to encode. Note that there is a loss * in precision as the double is converted to a float in the course of conversion. * * @param data the input byte array * @return the resulting float * @see net.semanticmetadata.lire.utils.SerializationUtils#toBytes(double) */ public static double toDouble(byte[] data) { return Double.longBitsToDouble(toLong(data)); } /** * Converts a byte[] array with size 8 to a long. <br/> * Taken from http://www.daniweb.com/software-development/java/code/216874 * * @param data the byte[] array to convert * @return the resulting long. * @see #toBytes(long) */ public static long toLong(byte[] data) { if (data == null || data.length != 8) return 0x0; // ---------- return (long) ( // (Below) convert to longs before shift because digits // are lost with ints beyond the 32-bit limit (long) (0xff & data[0]) << 56 | (long) (0xff & data[1]) << 48 | (long) (0xff & data[2]) << 40 | (long) (0xff & data[3]) << 32 | (long) (0xff & data[4]) << 24 | (long) (0xff & data[5]) << 16 | (long) (0xff & data[6]) << 8 | (long) (0xff & data[7]) << 0); } }