PLearn 0.1
ByteMemoryVMatrix.cc
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00001 // -*- C++ -*-
00002 
00003 // PLearn (A C++ Machine Learning Library)
00004 // Copyright (C) 1998 Pascal Vincent
00005 // Copyright (C) 1999-2001 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal
00006 // Copyright (C) 2002 Pascal Vincent, Julien Keable, Xavier Saint-Mleux
00007 //
00008 // Redistribution and use in source and binary forms, with or without
00009 // modification, are permitted provided that the following conditions are met:
00010 //
00011 //  1. Redistributions of source code must retain the above copyright
00012 //     notice, this list of conditions and the following disclaimer.
00013 //
00014 //  2. Redistributions in binary form must reproduce the above copyright
00015 //     notice, this list of conditions and the following disclaimer in the
00016 //     documentation and/or other materials provided with the distribution.
00017 //
00018 //  3. The name of the authors may not be used to endorse or promote
00019 //     products derived from this software without specific prior written
00020 //     permission.
00021 //
00022 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00023 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00024 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00025 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00026 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00027 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00028 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00029 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00030 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00031 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00032 //
00033 // This file is part of the PLearn library. For more information on the PLearn
00034 // library, go to the PLearn Web site at www.plearn.org
00035 
00036 
00037 /* *******************************************************
00038  * $Id: ByteMemoryVMatrix.cc 5557 2006-05-10 20:36:58Z lamblin $
00039  ******************************************************* */
00040 
00041 #include "ByteMemoryVMatrix.h"
00042 
00043 namespace PLearn {
00044 using namespace std;
00045 
00046 PLEARN_IMPLEMENT_OBJECT(ByteMemoryVMatrix, "ONE_LINE_DESCR", "ONE LINE HELP");
00047 
00050 ByteMemoryVMatrix::ByteMemoryVMatrix()
00051     : data(0)
00052 {
00053 }
00054 
00055 ByteMemoryVMatrix::ByteMemoryVMatrix(unsigned char* the_data,int the_length,int the_width, Vec the_scale)
00056     :inherited(the_length, the_width), data(the_data), scale(the_scale), offset_(the_scale.length())
00057 {
00058     if (the_scale.length() != width_)
00059         PLERROR("ByteMemoryVMatrix: inconsistent arguments (scale(%d),n_col(%d))",
00060                 the_scale.length(), width_);
00061 }
00062 
00063 ByteMemoryVMatrix::
00064 ByteMemoryVMatrix(unsigned char* the_data,int the_length,int the_width,
00065                   Vec the_scale, Vec the_offset)
00066     :VMatrix(the_length, the_width), data(the_data),
00067      scale(the_scale), offset_(the_offset)
00068 {
00069     if (the_scale.length() != width_ || the_offset.length()!=width_)
00070         PLERROR("ByteMemoryVMatrix: inconsistent arguments (scale(%d),offset(%d),n_col(%d))",
00071                 the_scale.length(), the_offset.length(), width_);
00072 }
00073 
00074 ByteMemoryVMatrix::ByteMemoryVMatrix(unsigned char* the_data,int the_length,int the_width,
00075                                      double the_scaling_factor,double the_offset)
00076     : VMatrix(the_length, the_width), data(the_data),
00077       scale(the_width, the_scaling_factor), offset_(the_width, the_offset)
00078 {
00079 }
00080 
00081 real ByteMemoryVMatrix::get(int i, int j) const
00082 {
00083     return ( data[i*width()+j] + offset_[j] ) * scale[j];
00084 }
00085 
00086 void ByteMemoryVMatrix::getSubRow(int i, int j, Vec samplevec) const
00087 {
00088     unsigned char* p = &data[i*width_];
00089     real *v = samplevec.data();
00090     real *s = scale.data();
00091     real *o = offset_.data();
00092     for (int jj=0; jj<samplevec.length(); jj++)
00093         v[jj] = s[j+jj] * (p[j+jj] + o[j+jj]);
00094 }
00095 
00096 } // end of namespace PLearn
00097 
00098 
00099 /*
00100   Local Variables:
00101   mode:c++
00102   c-basic-offset:4
00103   c-file-style:"stroustrup"
00104   c-file-offsets:((innamespace . 0)(inline-open . 0))
00105   indent-tabs-mode:nil
00106   fill-column:79
00107   End:
00108 */
00109 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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