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 "print.h"
  28 #include "archive.h"
  29 #include "utils.h"
  30
  31 namespace GiNaC {
  32
  33 GINAC_IMPLEMENT_REGISTERED_CLASS(fderivative, function)
  34
  35 //////////
  36 // default ctor, dtor, copy ctor, assignment operator and helpers
  37 //////////
  38
  39 fderivative::fderivative()
  40 {
  41         tinfo_key = TINFO_fderivative;
  42 }
  43
  44 void fderivative::copy(const fderivative & other)
  45 {
  46         inherited::copy(other);
  47         parameter_set = other.parameter_set;
  48 }
  49
  50 DEFAULT_DESTROY(fderivative)
  51
  52 //////////
  53 // other constructors
  54 //////////
  55
  56 fderivative::fderivative(unsigned ser, unsigned param, const exvector & args) : function(ser, args)
  57 {
  58         parameter_set.insert(param);
  59         tinfo_key = TINFO_fderivative;
  60 }
  61
  62 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  63 {
  64         tinfo_key = TINFO_fderivative;
  65 }
  66
  67 fderivative::fderivative(unsigned ser, const paramset & params, exvector * vp) : function(ser, vp), parameter_set(params)
  68 {
  69         tinfo_key = TINFO_fderivative;
  70 }
  71
  72 //////////
  73 // archiving
  74 //////////
  75
  76 fderivative::fderivative(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
  77 {
  78         unsigned i = 0;
  79         while (true) {
  80                 unsigned u;
  81                 if (n.find_unsigned("param", u, i))
  82                         parameter_set.insert(u);
  83                 else
  84                         break;
  85                 ++i;
  86         }
  87 }
  88
  89 void fderivative::archive(archive_node &n) const
  90 {
  91         inherited::archive(n);
  92         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
  93         while (i != end) {
  94                 n.add_unsigned("param", *i);
  95                 ++i;
  96         }
  97 }
  98
  99 DEFAULT_UNARCHIVE(fderivative)
 100
 101 //////////
 102 // functions overriding virtual functions from base classes
 103 //////////
 104
 105 void fderivative::print(const print_context & c, unsigned level) const
 106 {
 107         if (is_a<print_tree>(c)) {
 108
 109                 c.s << std::string(level, ' ') << class_name() << " "
 110                     << registered_functions()[serial].name
 111                     << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 112                     << ", nops=" << nops()
 113                     << ", params=";
 114                 paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 115                 --end;
 116                 while (i != end)
 117                         c.s << *i++ << ",";
 118                 c.s << *i << std::endl;
 119                 unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
 120                 for (size_t i=0; i<seq.size(); ++i)
 121                         seq[i].print(c, level + delta_indent);
 122                 c.s << std::string(level + delta_indent, ' ') << "=====" << std::endl;
 123
 124         } else {
 125
 126                 c.s << "D[";
 127                 paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 128                 --end;
 129                 while (i != end)
 130                         c.s << *i++ << ",";
 131                 c.s << *i << "](" << registered_functions()[serial].name << ")";
 132                 printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 133         }
 134 }
 135
 136 ex fderivative::eval(int level) const
 137 {
 138         if (level > 1) {
 139                 // first evaluate children, then we will end up here again
 140                 return fderivative(serial, parameter_set, evalchildren(level));
 141         }
 142
 143         // No parameters specified? Then return the function itself
 144         if (parameter_set.empty())
 145                 return function(serial, seq);
 146
 147         // If the function in question actually has a derivative, return it
 148         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 149                 return pderivative(*(parameter_set.begin()));
 150
 151         return this->hold();
 152 }
 153
 154 /** Numeric evaluation falls back to evaluation of arguments.
 155  *  @see basic::evalf */
 156 ex fderivative::evalf(int level) const
 157 {
 158         return basic::evalf(level);
 159 }
 160
 161 /** The series expansion of derivatives falls back to Taylor expansion.
 162  *  @see basic::series */
 163 ex fderivative::series(const relational & r, int order, unsigned options) const
 164 {
 165         return basic::series(r, order, options);
 166 }
 167
 168 ex fderivative::thisexprseq(const exvector & v) const
 169 {
 170         return fderivative(serial, parameter_set, v);
 171 }
 172
 173 ex fderivative::thisexprseq(exvector * vp) const
 174 {
 175         return fderivative(serial, parameter_set, vp);
 176 }
 177
 178 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 179  *  @see ex::diff */
 180 ex fderivative::derivative(const symbol & s) const
 181 {
 182         ex result;
 183         for (size_t i=0; i<seq.size(); i++) {
 184                 ex arg_diff = seq[i].diff(s);
 185                 if (!arg_diff.is_zero()) {
 186                         paramset ps = parameter_set;
 187                         ps.insert(i);
 188                         result += arg_diff * fderivative(serial, ps, seq);
 189                 }
 190         }
 191         return result;
 192 }
 193
 194 int fderivative::compare_same_type(const basic & other) const
 195 {
 196         GINAC_ASSERT(is_a<fderivative>(other));
 197         const fderivative & o = static_cast<const fderivative &>(other);
 198
 199         if (parameter_set != o.parameter_set)
 200                 return parameter_set < o.parameter_set ? -1 : 1;
 201         else
 202                 return inherited::compare_same_type(o);
 203 }
 204
 205 bool fderivative::is_equal_same_type(const basic & other) const
 206 {
 207         GINAC_ASSERT(is_a<fderivative>(other));
 208         const fderivative & o = static_cast<const fderivative &>(other);
 209
 210         if (parameter_set != o.parameter_set)
 211                 return false;
 212         else
 213                 return inherited::is_equal_same_type(o);
 214 }
 215
 216 bool fderivative::match_same_type(const basic & other) const
 217 {
 218         GINAC_ASSERT(is_a<fderivative>(other));
 219         const fderivative & o = static_cast<const fderivative &>(other);
 220
 221         return parameter_set == o.parameter_set;
 222 }
 223
 224 } // namespace GiNaC