CppAD: A C++ Algorithmic Differentiation Package 20110419
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00001 /* $Id$ */ 00002 # ifndef CPPAD_SUB_INCLUDED 00003 # define CPPAD_SUB_INCLUDED 00004 00005 /* -------------------------------------------------------------------------- 00006 CppAD: C++ Algorithmic Differentiation: Copyright (C) 2003-11 Bradley M. Bell 00007 00008 CppAD is distributed under multiple licenses. This distribution is under 00009 the terms of the 00010 Common Public License Version 1.0. 00011 00012 A copy of this license is included in the COPYING file of this distribution. 00013 Please visit http://www.coin-or.org/CppAD/ for information on other licenses. 00014 -------------------------------------------------------------------------- */ 00015 00016 // BEGIN CppAD namespace 00017 namespace CppAD { 00018 00019 template <class Base> 00020 AD<Base> operator - (const AD<Base> &left , const AD<Base> &right) 00021 { ADTape<Base> *tape = AD<Base>::tape_ptr(); 00022 size_t tape_id = 0; 00023 if( tape != CPPAD_NULL ) 00024 tape_id = tape->id_; 00025 00026 // id_ setting for parameters cannot match 0 00027 bool var_left = left.id_ == tape_id; 00028 bool var_right = right.id_ == tape_id; 00029 CPPAD_ASSERT_KNOWN( 00030 Parameter(left) || var_left , 00031 "-: left operand is a variable for a different thread" 00032 ); 00033 CPPAD_ASSERT_KNOWN( 00034 Parameter(right) || var_right , 00035 "-: right operand is a variable for a different thread" 00036 ); 00037 00038 AD<Base> result; 00039 result.value_ = left.value_ - right.value_; 00040 CPPAD_ASSERT_UNKNOWN( Parameter(result) ); 00041 00042 if( var_left ) 00043 { if( var_right ) 00044 { // result = variable - variable 00045 CPPAD_ASSERT_UNKNOWN( NumRes(SubvvOp) == 1 ); 00046 CPPAD_ASSERT_UNKNOWN( NumArg(SubvvOp) == 2 ); 00047 00048 // put operand addresses in tape 00049 tape->Rec_.PutArg(left.taddr_, right.taddr_); 00050 // put operator in the tape 00051 result.taddr_ = tape->Rec_.PutOp(SubvvOp); 00052 // make result a variable 00053 result.id_ = tape_id; 00054 } 00055 else if( IdenticalZero(right.value_) ) 00056 { // result = variable - 0 00057 result.make_variable(left.id_, left.taddr_); 00058 } 00059 else 00060 { // result = variable - parameter 00061 CPPAD_ASSERT_UNKNOWN( NumRes(SubvpOp) == 1 ); 00062 CPPAD_ASSERT_UNKNOWN( NumArg(SubvpOp) == 2 ); 00063 00064 // put operand addresses in tape 00065 size_t p = tape->Rec_.PutPar(right.value_); 00066 tape->Rec_.PutArg(left.taddr_, p); 00067 // put operator in the tape 00068 result.taddr_ = tape->Rec_.PutOp(SubvpOp); 00069 // make result a variable 00070 result.id_ = tape_id; 00071 } 00072 } 00073 else if( var_right ) 00074 { // result = parameter - variable 00075 CPPAD_ASSERT_UNKNOWN( NumRes(SubpvOp) == 1 ); 00076 CPPAD_ASSERT_UNKNOWN( NumArg(SubpvOp) == 2 ); 00077 00078 // put operand addresses in tape 00079 size_t p = tape->Rec_.PutPar(left.value_); 00080 tape->Rec_.PutArg(p, right.taddr_); 00081 // put operator in the tape 00082 result.taddr_ = tape->Rec_.PutOp(SubpvOp); 00083 // make result a variable 00084 result.id_ = tape_id; 00085 } 00086 return result; 00087 } 00088 00089 // convert other cases into the case above 00090 CPPAD_FOLD_AD_VALUED_BINARY_OPERATOR(-) 00091 00092 } // END CppAD namespace 00093 00094 # endif