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, std::auto_ptr<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::print(const print_context & c, unsigned level) const
  99 {
 100         // class function overrides print(), but we don't want that
 101         basic::print(c, level);
 102 }
 103
 104 void fderivative::do_print(const print_context & c, unsigned level) const
 105 {
 106         c.s << "D[";
 107         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 108         --end;
 109         while (i != end)
 110                 c.s << *i++ << ",";
 111         c.s << *i << "](" << registered_functions()[serial].name << ")";
 112         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 113 }
 114
 115 void fderivative::do_print_tree(const print_tree & c, unsigned level) const
 116 {
 117         c.s << std::string(level, ' ') << class_name() << " "
 118             << registered_functions()[serial].name << " @" << this
 119             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 120             << ", nops=" << nops()
 121             << ", params=";
 122         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 123         --end;
 124         while (i != end)
 125                 c.s << *i++ << ",";
 126         c.s << *i << std::endl;
 127         for (size_t i=0; i<seq.size(); ++i)
 128                 seq[i].print(c, level + c.delta_indent);
 129         c.s << std::string(level + c.delta_indent, ' ') << "=====" << std::endl;
 130 }
 131
 132 ex fderivative::eval(int level) const
 133 {
 134         if (level > 1) {
 135                 // first evaluate children, then we will end up here again
 136                 return fderivative(serial, parameter_set, evalchildren(level));
 137         }
 138
 139         // No parameters specified? Then return the function itself
 140         if (parameter_set.empty())
 141                 return function(serial, seq);
 142
 143         // If the function in question actually has a derivative, return it
 144         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 145                 return pderivative(*(parameter_set.begin()));
 146
 147         return this->hold();
 148 }
 149
 150 /** Numeric evaluation falls back to evaluation of arguments.
 151  *  @see basic::evalf */
 152 ex fderivative::evalf(int level) const
 153 {
 154         return basic::evalf(level);
 155 }
 156
 157 /** The series expansion of derivatives falls back to Taylor expansion.
 158  *  @see basic::series */
 159 ex fderivative::series(const relational & r, int order, unsigned options) const
 160 {
 161         return basic::series(r, order, options);
 162 }
 163
 164 ex fderivative::thiscontainer(const exvector & v) const
 165 {
 166         return fderivative(serial, parameter_set, v);
 167 }
 168
 169 ex fderivative::thiscontainer(std::auto_ptr<exvector> vp) const
 170 {
 171         return fderivative(serial, parameter_set, vp);
 172 }
 173
 174 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 175  *  @see ex::diff */
 176 ex fderivative::derivative(const symbol & s) const
 177 {
 178         ex result;
 179         for (size_t i=0; i<seq.size(); i++) {
 180                 ex arg_diff = seq[i].diff(s);
 181                 if (!arg_diff.is_zero()) {
 182                         paramset ps = parameter_set;
 183                         ps.insert(i);
 184                         result += arg_diff * fderivative(serial, ps, seq);
 185                 }
 186         }
 187         return result;
 188 }
 189
 190 int fderivative::compare_same_type(const basic & other) const
 191 {
 192         GINAC_ASSERT(is_a<fderivative>(other));
 193         const fderivative & o = static_cast<const fderivative &>(other);
 194
 195         if (parameter_set != o.parameter_set)
 196                 return parameter_set < o.parameter_set ? -1 : 1;
 197         else
 198                 return inherited::compare_same_type(o);
 199 }
 200
 201 bool fderivative::is_equal_same_type(const basic & other) const
 202 {
 203         GINAC_ASSERT(is_a<fderivative>(other));
 204         const fderivative & o = static_cast<const fderivative &>(other);
 205
 206         if (parameter_set != o.parameter_set)
 207                 return false;
 208         else
 209                 return inherited::is_equal_same_type(o);
 210 }
 211
 212 bool fderivative::match_same_type(const basic & other) const
 213 {
 214         GINAC_ASSERT(is_a<fderivative>(other));
 215         const fderivative & o = static_cast<const fderivative &>(other);
 216
 217         return parameter_set == o.parameter_set;
 218 }
 219
 220 } // namespace GiNaC