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Sacado_ELRFad_GeneralFad.hpp
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00001 // $Id$ 
00002 // $Source$ 
00003 // @HEADER
00004 // ***********************************************************************
00005 // 
00006 //                           Sacado Package
00007 //                 Copyright (2006) Sandia Corporation
00008 // 
00009 // Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
00010 // the U.S. Government retains certain rights in this software.
00011 // 
00012 // This library is free software; you can redistribute it and/or modify
00013 // it under the terms of the GNU Lesser General Public License as
00014 // published by the Free Software Foundation; either version 2.1 of the
00015 // License, or (at your option) any later version.
00016 //  
00017 // This library is distributed in the hope that it will be useful, but
00018 // WITHOUT ANY WARRANTY; without even the implied warranty of
00019 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00020 // Lesser General Public License for more details.
00021 //  
00022 // You should have received a copy of the GNU Lesser General Public
00023 // License along with this library; if not, write to the Free Software
00024 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
00025 // USA
00026 // Questions? Contact David M. Gay (dmgay@sandia.gov) or Eric T. Phipps
00027 // (etphipp@sandia.gov).
00028 // 
00029 // ***********************************************************************
00030 //
00031 // The forward-mode AD classes in Sacado are a derivative work of the
00032 // expression template classes in the Fad package by Nicolas Di Cesare.  
00033 // The following banner is included in the original Fad source code:
00034 //
00035 // ************ DO NOT REMOVE THIS BANNER ****************
00036 //
00037 //  Nicolas Di Cesare <Nicolas.Dicesare@ann.jussieu.fr>
00038 //  http://www.ann.jussieu.fr/~dicesare
00039 //
00040 //            CEMRACS 98 : C++ courses, 
00041 //         templates : new C++ techniques 
00042 //            for scientific computing 
00043 // 
00044 //********************************************************
00045 //
00046 //  A short implementation ( not all operators and 
00047 //  functions are overloaded ) of 1st order Automatic
00048 //  Differentiation in forward mode (FAD) using
00049 //  EXPRESSION TEMPLATES.
00050 //
00051 //********************************************************
00052 // @HEADER
00053 
00054 #ifndef SACADO_ELRFAD_GENERALFAD_HPP
00055 #define SACADO_ELRFAD_GENERALFAD_HPP
00056 
00057 #include "Sacado_ELRFad_Expression.hpp"
00058 #include "Sacado_dummy_arg.hpp"
00059 
00060 namespace Sacado {
00061 
00063   namespace ELRFad {
00064 
00066 
00071     template <typename T, typename Storage> 
00072     class GeneralFad : public Storage {
00073 
00074     public:
00075 
00077       typedef T value_type;
00078 
00080       typedef typename ScalarType<T>::type scalar_type;
00081 
00086 
00088       GeneralFad() : Storage(T(0.)), update_val_(true) {}
00089 
00091 
00094       GeneralFad(const T & x) : Storage(x), update_val_(true) {}
00095 
00097 
00100       GeneralFad(const int sz, const T & x) : 
00101   Storage(sz, x), update_val_(true) {}
00102 
00104 
00109       GeneralFad(const int sz, const int i, const T & x) : 
00110   Storage(sz, x), update_val_(true) { 
00111   this->fastAccessDx(i)=1.; 
00112       }
00113 
00115       GeneralFad(const GeneralFad& x) : 
00116   Storage(x), update_val_(x.update_val_) {}
00117 
00119       template <typename S> GeneralFad(const Expr<S>& x);
00120 
00122       ~GeneralFad() {}
00123 
00125 
00131       void diff(const int ith, const int n);
00132 
00134       void setUpdateValue(bool update_val) { update_val_ = update_val; }
00135 
00137       bool updateValue() const { return update_val_; }
00138 
00140       template <typename S>
00141       bool isEqualTo(const Expr<S>& x) const {
00142   typedef IsEqual<value_type> IE;
00143   if (x.size() != this->size()) return false;
00144   bool eq = IE::eval(x.val(), this->val());
00145   for (int i=0; i<this->size(); i++)
00146     eq = eq && IE::eval(x.dx(i), this->dx(i));
00147   return eq;
00148       }
00149 
00151 
00156 
00161       int availableSize() const { return this->length(); }
00162 
00164       bool hasFastAccess() const { return this->size()!=0;}
00165 
00167       bool isPassive() const { return this->size()==0;}
00168       
00170       void setIsConstant(bool is_const) { 
00171   if (is_const && this->size()!=0)
00172     this->resize(0);
00173       }
00174     
00176 
00181 
00183       GeneralFad& operator=(const T& val);
00184 
00186       GeneralFad& 
00187       operator=(const GeneralFad& x);
00188 
00190       template <typename S> 
00191       GeneralFad& operator=(const Expr<S>& x); 
00192 
00194 
00199 
00201       GeneralFad& operator += (const T& x);
00202 
00204       GeneralFad& operator -= (const T& x);
00205 
00207       GeneralFad& operator *= (const T& x);
00208 
00210       GeneralFad& operator /= (const T& x);
00211 
00213 
00217       GeneralFad& operator += (const typename dummy<value_type,scalar_type>::type& x);
00218 
00220 
00224       GeneralFad& operator -= (const typename dummy<value_type,scalar_type>::type& x);
00225 
00227 
00231       GeneralFad& operator *= (const typename dummy<value_type,scalar_type>::type& x);
00232 
00234 
00238       GeneralFad& operator /= (const typename dummy<value_type,scalar_type>::type& x);
00239 
00241       template <typename S> 
00242       GeneralFad& operator += (const Expr<S>& x);
00243 
00245       template <typename S> 
00246       GeneralFad& operator -= (const Expr<S>& x);
00247   
00249       template <typename S> 
00250       GeneralFad& operator *= (const Expr<S>& x);
00251 
00253       template <typename S> 
00254       GeneralFad& operator /= (const Expr<S>& x);
00255 
00257 
00258     protected:
00259 
00261       bool update_val_;
00262 
00263       // Functor for mpl::for_each to compute the local accumulation
00264       // of a tangent derivative
00265       template <typename ExprT>
00266       struct FastLocalAccumOp {
00267   typedef typename ExprT::value_type value_type;
00268   static const int N = ExprT::num_args;
00269   const ExprT& x;
00270   mutable value_type t;
00271   value_type partials[N];
00272   const typename ExprT::base_expr_type* args[N];
00273   int i;
00274   inline FastLocalAccumOp(const ExprT& x_) : x(x_) { 
00275     x.computePartials(value_type(1.), partials); 
00276     for (int j=0; j<N; j++)
00277       args[j] = &(x.getArg(j));
00278   }
00279   template <typename ArgT>
00280   inline void operator () (ArgT arg) const {
00281     const int Arg = ArgT::value;
00282     t += partials[Arg] * args[Arg]->fastAccessDx(i);
00283   }
00284       };
00285 
00286       template <typename ExprT>
00287       struct SlowLocalAccumOp : FastLocalAccumOp<ExprT> {
00288   inline SlowLocalAccumOp(const ExprT& x_) : 
00289     FastLocalAccumOp<ExprT>(x_) {}
00290   template <typename ArgT>
00291   inline void operator () (ArgT arg) const {
00292     const int Arg = ArgT::value;
00293     if (this->x.template isActive<Arg>())
00294       this->t += this->partials[Arg] * this->args[Arg]->fastAccessDx(this->i);
00295   }
00296       };
00297 
00298     }; // class GeneralFad
00299 
00300     
00301     template <typename T, typename Storage>
00302     std::ostream& operator << (std::ostream& os, 
00303                                const GeneralFad<T,Storage>& x) {
00304       os << x.val() << " [";
00305       
00306       for (int i=0; i< x.size(); i++) {
00307         os << " " << x.dx(i);
00308       }
00309 
00310       os << " ]";
00311       return os;
00312     }
00313 
00314   } // namespace ELRFad
00315 
00316 } // namespace Sacado
00317 
00318 #include "Sacado_ELRFad_GeneralFadImp.hpp"
00319 
00320 #endif // SACADO_ELRFAD_GENERALFAD_HPP
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