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