PLearn 0.1
VecCompressor.h
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00001 // -*- C++ -*-
00002 
00003 // VecCompressor.h
00004 // Copyright (C) 2001 Pascal Vincent
00005 // Copyright (C) 2002 Pascal Vincent, Julien Keable, Xavier Saint-Mleux
00006 //
00007 // Redistribution and use in source and binary forms, with or without
00008 // modification, are permitted provided that the following conditions are met:
00009 // 
00010 //  1. Redistributions of source code must retain the above copyright
00011 //     notice, this list of conditions and the following disclaimer.
00012 // 
00013 //  2. Redistributions in binary form must reproduce the above copyright
00014 //     notice, this list of conditions and the following disclaimer in the
00015 //     documentation and/or other materials provided with the distribution.
00016 // 
00017 //  3. The name of the authors may not be used to endorse or promote
00018 //     products derived from this software without specific prior written
00019 //     permission.
00020 // 
00021 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00022 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00023 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00024 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00025 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00026 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00027 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00028 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00029 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00030 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00031 // 
00032 // This file is part of the PLearn library. For more information on the PLearn
00033 // library, go to the PLearn Web site at www.plearn.org
00034 
00035 
00036 /* *******************************************************      
00037  * $Id: VecCompressor.h 5176 2006-03-13 22:40:51Z lamblin $
00038  ******************************************************* */
00039 
00040 
00041 #ifndef VecCompressor_INC
00042 #define VecCompressor_INC
00043 
00044 #include "TMat.h"
00045 
00046 namespace PLearn {
00047 using namespace std;
00048  
00049 
00058 class VecCompressor
00059 {
00060 protected:
00061 
00062     static inline bool issmallint(real x)
00063     { int intx = int(x); return fast_exact_is_equal(floor(x), x) && intx<=127 && intx>=-127; }
00064 
00065     static inline bool is0(real x)
00066     { return fast_exact_is_equal(x, 0.); }
00067 
00068     static inline bool isI(real x)
00069     { return !fast_exact_is_equal(x, 0.) && issmallint(x); }
00070 
00071     static inline bool isF(real x)
00072     { return !fast_exact_is_equal(x, 0.) && !issmallint(x); }
00073   
00074 public:
00079     static signed char* compressVec(const Vec& v, signed char* data);
00080 
00083     static void uncompressVec(signed char* data, const Vec& v);  
00084 
00087     static void writeCompressedVec(ostream& out, const Vec& v);
00088 
00091     static void readCompressedVec(istream& in, const Vec& v); 
00092 
00095     static size_t worstCaseSize(int n)
00096     { return 2+4*n+n/128; }
00097 };
00098 
00099 } // end of namespace PLearn
00100 #endif
00101 
00102 
00103 /*
00104   Local Variables:
00105   mode:c++
00106   c-basic-offset:4
00107   c-file-style:"stroustrup"
00108   c-file-offsets:((innamespace . 0)(inline-open . 0))
00109   indent-tabs-mode:nil
00110   fill-column:79
00111   End:
00112 */
00113 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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