PLearn 0.1
Var_operators.cc
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00001 
00002 // -*- C++ -*-
00003 
00004 // PLearn (A C++ Machine Learning Library)
00005 // Copyright (C) 1998 Pascal Vincent
00006 // Copyright (C) 1999-2002 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal
00007 // Copyright (C) 2001-2002 Nicolas Chapados, Ichiro Takeuchi, Jean-Sebastien Senecal
00008 // Copyright (C) 2002 Xiangdong Wang, Christian Dorion
00009 
00010 // Redistribution and use in source and binary forms, with or without
00011 // modification, are permitted provided that the following conditions are met:
00012 // 
00013 //  1. Redistributions of source code must retain the above copyright
00014 //     notice, this list of conditions and the following disclaimer.
00015 // 
00016 //  2. Redistributions in binary form must reproduce the above copyright
00017 //     notice, this list of conditions and the following disclaimer in the
00018 //     documentation and/or other materials provided with the distribution.
00019 // 
00020 //  3. The name of the authors may not be used to endorse or promote
00021 //     products derived from this software without specific prior written
00022 //     permission.
00023 // 
00024 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00025 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00026 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00027 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00028 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00029 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00030 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00031 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00032 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00033 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00034 // 
00035 // This file is part of the PLearn library. For more information on the PLearn
00036 // library, go to the PLearn Web site at www.plearn.org
00037 
00038 
00039 /* *******************************************************      
00040  * $Id: Var_operators.cc 9099 2008-06-03 21:58:54Z plearner $
00041  * This file is part of the PLearn library.
00042  ******************************************************* */
00043 
00044 #include "Var_operators.h"
00045 
00046 #include "PlusConstantVariable.h"
00047 #include "PlusScalarVariable.h"
00048 #include "PlusRowVariable.h"
00049 #include "PlusColumnVariable.h"
00050 #include "PlusVariable.h"
00051 
00052 #include "MinusScalarVariable.h"
00053 #include "NegateElementsVariable.h"
00054 #include "MinusRowVariable.h"
00055 #include "MinusColumnVariable.h"
00056 #include "MinusVariable.h"
00057 
00058 #include "TimesScalarVariable.h"
00059 #include "TimesColumnVariable.h"
00060 #include "TimesRowVariable.h"
00061 #include "TimesVariable.h"
00062 
00063 #include "InvertElementsVariable.h"
00064 #include "DivVariable.h"
00065 
00066 #include "EqualVariable.h"
00067 
00068 namespace PLearn {
00069 using namespace std;
00070 
00071 Var operator+(Var v, real cte)
00072 { return new PlusConstantVariable(v,cte); }
00073 
00074 Var operator+(real cte, Var v)
00075 { return new PlusConstantVariable(v,cte); }
00076 
00077 Var operator-(Var v, real cte)
00078 { return new PlusConstantVariable(v,-cte); }
00079 
00080 Var operator+(Var v1, Var v2)
00081 { 
00082     if(v2->isScalar())
00083         return new PlusScalarVariable(v1,v2);
00084     else if(v1->isScalar())
00085         return new PlusScalarVariable(v2,v1);
00086     else if(v2->isRowVec())
00087         return new PlusRowVariable(v1,v2);
00088     else if(v1->isRowVec())
00089         return new PlusRowVariable(v2,v1);
00090     else if(v2->isColumnVec())
00091         return new PlusColumnVariable(v1,v2);
00092     else if(v1->isColumnVec())
00093         return new PlusColumnVariable(v2,v1);
00094     else
00095         return new PlusVariable(v1,v2);
00096 }
00097 
00098 void operator+=(Var& v1, const Var& v2)
00099 {
00100     if (!v2.isNull())
00101     {
00102         if (v1.isNull())
00103             v1 = v2;
00104         else 
00105             v1 = v1 + v2;
00106     }
00107 }
00108 
00109 Var operator-(Var v1, Var v2)
00110 { 
00111     if(v2->isScalar())
00112         return new MinusScalarVariable(v1,v2);
00113     else if(v1->isScalar())
00114         return new PlusScalarVariable(new NegateElementsVariable(v2), v1);
00115     else if(v2->isRowVec())
00116         return new MinusRowVariable(v1,v2);
00117     else if(v1->isRowVec())
00118         return new NegateElementsVariable(new MinusRowVariable(v2,v1));
00119     else if(v2->isColumnVec())
00120         return new MinusColumnVariable(v1,v2);
00121     else if(v1->isColumnVec())
00122         return new PlusColumnVariable(new NegateElementsVariable(v2), v1);
00123     else
00124         return new MinusVariable(v1,v2);
00125 }
00126 
00127 void operator-=(Var& v1, const Var& v2)
00128 {
00129     if (!v2.isNull())
00130     {
00131         if (v1.isNull())
00132             v1 = -v2;
00133         else
00134             v1 = v1 - v2;
00135     }
00136 }
00137 
00138 Var operator-(real cte, Var v)
00139 { return new PlusConstantVariable(new NegateElementsVariable(v),cte); }
00140 
00141 
00143 Var operator*(Var v1, Var v2)
00144 { 
00145     if(v2->isScalar())
00146         return new TimesScalarVariable(v1,v2);
00147     else if(v1->isScalar())
00148         return new TimesScalarVariable(v2,v1);
00149     else if(v2->isColumnVec())
00150         return new TimesColumnVariable(v1,v2);
00151     else if(v1->isColumnVec())
00152         return new TimesColumnVariable(v2,v1);
00153     else if(v2->isRowVec())
00154         return new TimesRowVariable(v1,v2);
00155     else if(v1->isRowVec())
00156         return new TimesRowVariable(v2,v1);
00157     else 
00158         return new TimesVariable(v1,v2); 
00159 }
00160 
00161 Var operator/(real cte, Var v)
00162 {
00163     if(fast_exact_is_equal(cte, 1.0))
00164         return invertElements(v);
00165     else
00166         return cte*invertElements(v);
00167 }
00168 
00169 Var operator/(Var v1, Var v2)
00170 {
00171     if(v1->length()==v2->length() && v1->width()==v2->width())
00172         return new DivVariable(v1,v2);
00173     else
00174         return v1*invertElements(v2);
00175 }
00176 
00177 Var operator==(Var v1, Var v2)
00178 { return isequal(v1,v2); }
00179 
00180 Var operator!=(Var v1, Var v2)
00181 { return (1.0 - isequal(v1,v2) ); }
00182 
00183 Var isdifferent(Var v1, Var v2)
00184 { return (1.0 - isequal(v1,v2) ); }
00185 
00186 
00187 } // end of namespace PLearn
00188 
00189 
00190 /*
00191   Local Variables:
00192   mode:c++
00193   c-basic-offset:4
00194   c-file-style:"stroustrup"
00195   c-file-offsets:((innamespace . 0)(inline-open . 0))
00196   indent-tabs-mode:nil
00197   fill-column:79
00198   End:
00199 */
00200 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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