CppAD: A C++ Algorithmic Differentiation Package
20130918
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00001 /* $Id$ */ 00002 # ifndef CPPAD_SUB_EQ_INCLUDED 00003 # define CPPAD_SUB_EQ_INCLUDED 00004 00005 /* -------------------------------------------------------------------------- 00006 CppAD: C++ Algorithmic Differentiation: Copyright (C) 2003-12 Bradley M. Bell 00007 00008 CppAD is distributed under multiple licenses. This distribution is under 00009 the terms of the 00010 Eclipse 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>& AD<Base>::operator -= (const AD<Base> &right) 00021 { 00022 // compute the Base part 00023 Base left; 00024 left = value_; 00025 value_ -= right.value_; 00026 00027 // check if there is a recording in progress 00028 ADTape<Base>* tape = AD<Base>::tape_ptr(); 00029 if( tape == CPPAD_NULL ) 00030 return *this; 00031 tape_id_t tape_id = tape->id_; 00032 00033 // tape_id cannot match the default value for tape_id_; i.e., 0 00034 CPPAD_ASSERT_UNKNOWN( tape_id > 0 ); 00035 bool var_left = tape_id_ == tape_id; 00036 bool var_right = right.tape_id_ == tape_id; 00037 00038 if( var_left ) 00039 { if( var_right ) 00040 { // this = variable - variable 00041 CPPAD_ASSERT_UNKNOWN( NumRes(SubvvOp) == 1 ); 00042 CPPAD_ASSERT_UNKNOWN( NumArg(SubvvOp) == 2 ); 00043 00044 // put operand addresses in tape 00045 tape->Rec_.PutArg(taddr_, right.taddr_); 00046 // put operator in the tape 00047 taddr_ = tape->Rec_.PutOp(SubvvOp); 00048 // make this a variable 00049 CPPAD_ASSERT_UNKNOWN( tape_id_ == tape_id ); 00050 } 00051 else if( IdenticalZero( right.value_ ) ) 00052 { // this = variable - 0 00053 } 00054 else 00055 { // this = variable - parameter 00056 CPPAD_ASSERT_UNKNOWN( NumRes(SubvpOp) == 1 ); 00057 CPPAD_ASSERT_UNKNOWN( NumArg(SubvpOp) == 2 ); 00058 00059 // put operand addresses in tape 00060 addr_t p = tape->Rec_.PutPar(right.value_); 00061 tape->Rec_.PutArg(taddr_, p); 00062 // put operator in the tape 00063 taddr_ = tape->Rec_.PutOp(SubvpOp); 00064 // make this a variable 00065 CPPAD_ASSERT_UNKNOWN( tape_id_ == tape_id ); 00066 } 00067 } 00068 else if( var_right ) 00069 { // this = parameter - variable 00070 CPPAD_ASSERT_UNKNOWN( NumRes(SubpvOp) == 1 ); 00071 CPPAD_ASSERT_UNKNOWN( NumArg(SubpvOp) == 2 ); 00072 00073 // put operand addresses in tape 00074 addr_t p = tape->Rec_.PutPar(left); 00075 tape->Rec_.PutArg(p, right.taddr_); 00076 // put operator in the tape 00077 taddr_ = tape->Rec_.PutOp(SubpvOp); 00078 // make this a variable 00079 tape_id_ = tape_id; 00080 } 00081 return *this; 00082 } 00083 00084 CPPAD_FOLD_ASSIGNMENT_OPERATOR(-=) 00085 00086 } // END CppAD namespace 00087 00088 # endif