ginac/fderivative.cpp

   1 /** @file fderivative.cpp
   2  *
   3  *  Implementation of abstract derivatives of functions. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2003 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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_tree>(&fderivative::do_print_tree))
  35
  36 //////////
  37 // default constructor
  38 //////////
  39
  40 fderivative::fderivative()
  41 {
  42         tinfo_key = TINFO_fderivative;
  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         tinfo_key = TINFO_fderivative;
  53 }
  54
  55 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  56 {
  57         tinfo_key = TINFO_fderivative;
  58 }
  59
  60 fderivative::fderivative(unsigned ser, const paramset & params, exvector * vp) : function(ser, vp), parameter_set(params)
  61 {
  62         tinfo_key = TINFO_fderivative;
  63 }
  64
  65 //////////
  66 // archiving
  67 //////////
  68
  69 fderivative::fderivative(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
  70 {
  71         unsigned i = 0;
  72         while (true) {
  73                 unsigned u;
  74                 if (n.find_unsigned("param", u, i))
  75                         parameter_set.insert(u);
  76                 else
  77                         break;
  78                 ++i;
  79         }
  80 }
  81
  82 void fderivative::archive(archive_node &n) const
  83 {
  84         inherited::archive(n);
  85         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
  86         while (i != end) {
  87                 n.add_unsigned("param", *i);
  88                 ++i;
  89         }
  90 }
  91
  92 DEFAULT_UNARCHIVE(fderivative)
  93
  94 //////////
  95 // functions overriding virtual functions from base classes
  96 //////////
  97
  98 void fderivative::do_print(const print_context & c, unsigned level) const
  99 {
 100         c.s << "D[";
 101         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 102         --end;
 103         while (i != end)
 104                 c.s << *i++ << ",";
 105         c.s << *i << "](" << registered_functions()[serial].name << ")";
 106         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 107 }
 108
 109 void fderivative::do_print_tree(const print_tree & c, unsigned level) const
 110 {
 111         c.s << std::string(level, ' ') << class_name() << " "
 112             << registered_functions()[serial].name
 113             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 114             << ", nops=" << nops()
 115             << ", params=";
 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 << std::endl;
 121         for (size_t i=0; i<seq.size(); ++i)
 122                 seq[i].print(c, level + c.delta_indent);
 123         c.s << std::string(level + c.delta_indent, ' ') << "=====" << std::endl;
 124 }
 125
 126 ex fderivative::eval(int level) const
 127 {
 128         if (level > 1) {
 129                 // first evaluate children, then we will end up here again
 130                 return fderivative(serial, parameter_set, evalchildren(level));
 131         }
 132
 133         // No parameters specified? Then return the function itself
 134         if (parameter_set.empty())
 135                 return function(serial, seq);
 136
 137         // If the function in question actually has a derivative, return it
 138         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 139                 return pderivative(*(parameter_set.begin()));
 140
 141         return this->hold();
 142 }
 143
 144 /** Numeric evaluation falls back to evaluation of arguments.
 145  *  @see basic::evalf */
 146 ex fderivative::evalf(int level) const
 147 {
 148         return basic::evalf(level);
 149 }
 150
 151 /** The series expansion of derivatives falls back to Taylor expansion.
 152  *  @see basic::series */
 153 ex fderivative::series(const relational & r, int order, unsigned options) const
 154 {
 155         return basic::series(r, order, options);
 156 }
 157
 158 ex fderivative::thiscontainer(const exvector & v) const
 159 {
 160         return fderivative(serial, parameter_set, v);
 161 }
 162
 163 ex fderivative::thiscontainer(exvector * vp) const
 164 {
 165         return fderivative(serial, parameter_set, vp);
 166 }
 167
 168 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 169  *  @see ex::diff */
 170 ex fderivative::derivative(const symbol & s) const
 171 {
 172         ex result;
 173         for (size_t i=0; i<seq.size(); i++) {
 174                 ex arg_diff = seq[i].diff(s);
 175                 if (!arg_diff.is_zero()) {
 176                         paramset ps = parameter_set;
 177                         ps.insert(i);
 178                         result += arg_diff * fderivative(serial, ps, seq);
 179                 }
 180         }
 181         return result;
 182 }
 183
 184 int fderivative::compare_same_type(const basic & other) const
 185 {
 186         GINAC_ASSERT(is_a<fderivative>(other));
 187         const fderivative & o = static_cast<const fderivative &>(other);
 188
 189         if (parameter_set != o.parameter_set)
 190                 return parameter_set < o.parameter_set ? -1 : 1;
 191         else
 192                 return inherited::compare_same_type(o);
 193 }
 194
 195 bool fderivative::is_equal_same_type(const basic & other) const
 196 {
 197         GINAC_ASSERT(is_a<fderivative>(other));
 198         const fderivative & o = static_cast<const fderivative &>(other);
 199
 200         if (parameter_set != o.parameter_set)
 201                 return false;
 202         else
 203                 return inherited::is_equal_same_type(o);
 204 }
 205
 206 bool fderivative::match_same_type(const basic & other) const
 207 {
 208         GINAC_ASSERT(is_a<fderivative>(other));
 209         const fderivative & o = static_cast<const fderivative &>(other);
 210
 211         return parameter_set == o.parameter_set;
 212 }
 213
 214 } // namespace GiNaC