ginac/fderivative.cpp

   1 /** @file fderivative.cpp
   2  *
   3  *  Implementation of abstract derivatives of functions. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2008 Johannes Gutenberg University Mainz, Germany
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  21  */
  22
  23 #include <iostream>
  24
  25 #include "fderivative.h"
  26 #include "operators.h"
  27 #include "archive.h"
  28 #include "utils.h"
  29
  30 namespace GiNaC {
  31
  32 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(fderivative, function,
  33   print_func<print_context>(&fderivative::do_print).
  34   print_func<print_csrc>(&fderivative::do_print_csrc).
  35   print_func<print_tree>(&fderivative::do_print_tree))
  36
  37 //////////
  38 // default constructor
  39 //////////
  40
  41 fderivative::fderivative()
  42 {
  43 }
  44
  45 //////////
  46 // other constructors
  47 //////////
  48
  49 fderivative::fderivative(unsigned ser, unsigned param, const exvector & args) : function(ser, args)
  50 {
  51         parameter_set.insert(param);
  52 }
  53
  54 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  55 {
  56 }
  57
  58 fderivative::fderivative(unsigned ser, const paramset & params, std::auto_ptr<exvector> vp) : function(ser, vp), parameter_set(params)
  59 {
  60 }
  61
  62 //////////
  63 // archiving
  64 //////////
  65
  66 fderivative::fderivative(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
  67 {
  68         unsigned i = 0;
  69         while (true) {
  70                 unsigned u;
  71                 if (n.find_unsigned("param", u, i))
  72                         parameter_set.insert(u);
  73                 else
  74                         break;
  75                 ++i;
  76         }
  77 }
  78
  79 void fderivative::archive(archive_node &n) const
  80 {
  81         inherited::archive(n);
  82         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
  83         while (i != end) {
  84                 n.add_unsigned("param", *i);
  85                 ++i;
  86         }
  87 }
  88
  89 DEFAULT_UNARCHIVE(fderivative)
  90
  91 //////////
  92 // functions overriding virtual functions from base classes
  93 //////////
  94
  95 void fderivative::print(const print_context & c, unsigned level) const
  96 {
  97         // class function overrides print(), but we don't want that
  98         basic::print(c, level);
  99 }
 100
 101 void fderivative::do_print(const print_context & c, unsigned level) const
 102 {
 103         c.s << "D[";
 104         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 105         --end;
 106         while (i != end) {
 107                 c.s << *i++ << ",";
 108         }
 109         c.s << *i << "](" << registered_functions()[serial].name << ")";
 110         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 111 }
 112
 113 void fderivative::do_print_csrc(const print_csrc & c, unsigned level) const
 114 {
 115         c.s << "D_";
 116         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 117         --end;
 118         while (i != end)
 119                 c.s << *i++ << "_";
 120         c.s << *i << "_" << registered_functions()[serial].name;
 121         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 122 }
 123
 124 void fderivative::do_print_tree(const print_tree & c, unsigned level) const
 125 {
 126         c.s << std::string(level, ' ') << class_name() << " "
 127             << registered_functions()[serial].name << " @" << this
 128             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 129             << ", nops=" << nops()
 130             << ", params=";
 131         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 132         --end;
 133         while (i != end)
 134                 c.s << *i++ << ",";
 135         c.s << *i << std::endl;
 136         for (size_t i=0; i<seq.size(); ++i)
 137                 seq[i].print(c, level + c.delta_indent);
 138         c.s << std::string(level + c.delta_indent, ' ') << "=====" << std::endl;
 139 }
 140
 141 ex fderivative::eval(int level) const
 142 {
 143         if (level > 1) {
 144                 // first evaluate children, then we will end up here again
 145                 return fderivative(serial, parameter_set, evalchildren(level));
 146         }
 147
 148         // No parameters specified? Then return the function itself
 149         if (parameter_set.empty())
 150                 return function(serial, seq);
 151
 152         // If the function in question actually has a derivative, return it
 153         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 154                 return pderivative(*(parameter_set.begin()));
 155
 156         return this->hold();
 157 }
 158
 159 /** Numeric evaluation falls back to evaluation of arguments.
 160  *  @see basic::evalf */
 161 ex fderivative::evalf(int level) const
 162 {
 163         return basic::evalf(level);
 164 }
 165
 166 /** The series expansion of derivatives falls back to Taylor expansion.
 167  *  @see basic::series */
 168 ex fderivative::series(const relational & r, int order, unsigned options) const
 169 {
 170         return basic::series(r, order, options);
 171 }
 172
 173 ex fderivative::thiscontainer(const exvector & v) const
 174 {
 175         return fderivative(serial, parameter_set, v);
 176 }
 177
 178 ex fderivative::thiscontainer(std::auto_ptr<exvector> vp) const
 179 {
 180         return fderivative(serial, parameter_set, vp);
 181 }
 182
 183 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 184  *  @see ex::diff */
 185 ex fderivative::derivative(const symbol & s) const
 186 {
 187         ex result;
 188         for (size_t i=0; i<seq.size(); i++) {
 189                 ex arg_diff = seq[i].diff(s);
 190                 if (!arg_diff.is_zero()) {
 191                         paramset ps = parameter_set;
 192                         ps.insert(i);
 193                         result += arg_diff * fderivative(serial, ps, seq);
 194                 }
 195         }
 196         return result;
 197 }
 198
 199 int fderivative::compare_same_type(const basic & other) const
 200 {
 201         GINAC_ASSERT(is_a<fderivative>(other));
 202         const fderivative & o = static_cast<const fderivative &>(other);
 203
 204         if (parameter_set != o.parameter_set)
 205                 return parameter_set < o.parameter_set ? -1 : 1;
 206         else
 207                 return inherited::compare_same_type(o);
 208 }
 209
 210 bool fderivative::is_equal_same_type(const basic & other) const
 211 {
 212         GINAC_ASSERT(is_a<fderivative>(other));
 213         const fderivative & o = static_cast<const fderivative &>(other);
 214
 215         if (parameter_set != o.parameter_set)
 216                 return false;
 217         else
 218                 return inherited::is_equal_same_type(o);
 219 }
 220
 221 bool fderivative::match_same_type(const basic & other) const
 222 {
 223         GINAC_ASSERT(is_a<fderivative>(other));
 224         const fderivative & o = static_cast<const fderivative &>(other);
 225
 226         return parameter_set == o.parameter_set && inherited::match_same_type(other);
 227 }
 228
 229 } // namespace GiNaC