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         tinfo_key = &fderivative::tinfo_static;
  44 }
  45
  46 //////////
  47 // other constructors
  48 //////////
  49
  50 fderivative::fderivative(unsigned ser, unsigned param, const exvector & args) : function(ser, args)
  51 {
  52         parameter_set.insert(param);
  53         tinfo_key = &fderivative::tinfo_static;
  54 }
  55
  56 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  57 {
  58         tinfo_key = &fderivative::tinfo_static;
  59 }
  60
  61 fderivative::fderivative(unsigned ser, const paramset & params, std::auto_ptr<exvector> vp) : function(ser, vp), parameter_set(params)
  62 {
  63         tinfo_key = &fderivative::tinfo_static;
  64 }
  65
  66 //////////
  67 // archiving
  68 //////////
  69
  70 fderivative::fderivative(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
  71 {
  72         unsigned i = 0;
  73         while (true) {
  74                 unsigned u;
  75                 if (n.find_unsigned("param", u, i))
  76                         parameter_set.insert(u);
  77                 else
  78                         break;
  79                 ++i;
  80         }
  81 }
  82
  83 void fderivative::archive(archive_node &n) const
  84 {
  85         inherited::archive(n);
  86         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
  87         while (i != end) {
  88                 n.add_unsigned("param", *i);
  89                 ++i;
  90         }
  91 }
  92
  93 DEFAULT_UNARCHIVE(fderivative)
  94
  95 //////////
  96 // functions overriding virtual functions from base classes
  97 //////////
  98
  99 void fderivative::print(const print_context & c, unsigned level) const
 100 {
 101         // class function overrides print(), but we don't want that
 102         basic::print(c, level);
 103 }
 104
 105 void fderivative::do_print(const print_context & c, unsigned level) const
 106 {
 107         c.s << "D[";
 108         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 109         --end;
 110         while (i != end) {
 111                 c.s << *i++ << ",";
 112         }
 113         c.s << *i << "](" << registered_functions()[serial].name << ")";
 114         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 115 }
 116
 117 void fderivative::do_print_csrc(const print_csrc & c, unsigned level) const
 118 {
 119         c.s << "D_";
 120         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 121         --end;
 122         while (i != end)
 123                 c.s << *i++ << "_";
 124         c.s << *i << "_" << registered_functions()[serial].name;
 125         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 126 }
 127
 128 void fderivative::do_print_tree(const print_tree & c, unsigned level) const
 129 {
 130         c.s << std::string(level, ' ') << class_name() << " "
 131             << registered_functions()[serial].name << " @" << this
 132             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 133             << ", nops=" << nops()
 134             << ", params=";
 135         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 136         --end;
 137         while (i != end)
 138                 c.s << *i++ << ",";
 139         c.s << *i << std::endl;
 140         for (size_t i=0; i<seq.size(); ++i)
 141                 seq[i].print(c, level + c.delta_indent);
 142         c.s << std::string(level + c.delta_indent, ' ') << "=====" << std::endl;
 143 }
 144
 145 ex fderivative::eval(int level) const
 146 {
 147         if (level > 1) {
 148                 // first evaluate children, then we will end up here again
 149                 return fderivative(serial, parameter_set, evalchildren(level));
 150         }
 151
 152         // No parameters specified? Then return the function itself
 153         if (parameter_set.empty())
 154                 return function(serial, seq);
 155
 156         // If the function in question actually has a derivative, return it
 157         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 158                 return pderivative(*(parameter_set.begin()));
 159
 160         return this->hold();
 161 }
 162
 163 /** Numeric evaluation falls back to evaluation of arguments.
 164  *  @see basic::evalf */
 165 ex fderivative::evalf(int level) const
 166 {
 167         return basic::evalf(level);
 168 }
 169
 170 /** The series expansion of derivatives falls back to Taylor expansion.
 171  *  @see basic::series */
 172 ex fderivative::series(const relational & r, int order, unsigned options) const
 173 {
 174         return basic::series(r, order, options);
 175 }
 176
 177 ex fderivative::thiscontainer(const exvector & v) const
 178 {
 179         return fderivative(serial, parameter_set, v);
 180 }
 181
 182 ex fderivative::thiscontainer(std::auto_ptr<exvector> vp) const
 183 {
 184         return fderivative(serial, parameter_set, vp);
 185 }
 186
 187 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 188  *  @see ex::diff */
 189 ex fderivative::derivative(const symbol & s) const
 190 {
 191         ex result;
 192         for (size_t i=0; i<seq.size(); i++) {
 193                 ex arg_diff = seq[i].diff(s);
 194                 if (!arg_diff.is_zero()) {
 195                         paramset ps = parameter_set;
 196                         ps.insert(i);
 197                         result += arg_diff * fderivative(serial, ps, seq);
 198                 }
 199         }
 200         return result;
 201 }
 202
 203 int fderivative::compare_same_type(const basic & other) const
 204 {
 205         GINAC_ASSERT(is_a<fderivative>(other));
 206         const fderivative & o = static_cast<const fderivative &>(other);
 207
 208         if (parameter_set != o.parameter_set)
 209                 return parameter_set < o.parameter_set ? -1 : 1;
 210         else
 211                 return inherited::compare_same_type(o);
 212 }
 213
 214 bool fderivative::is_equal_same_type(const basic & other) const
 215 {
 216         GINAC_ASSERT(is_a<fderivative>(other));
 217         const fderivative & o = static_cast<const fderivative &>(other);
 218
 219         if (parameter_set != o.parameter_set)
 220                 return false;
 221         else
 222                 return inherited::is_equal_same_type(o);
 223 }
 224
 225 bool fderivative::match_same_type(const basic & other) const
 226 {
 227         GINAC_ASSERT(is_a<fderivative>(other));
 228         const fderivative & o = static_cast<const fderivative &>(other);
 229
 230         return parameter_set == o.parameter_set && inherited::match_same_type(other);
 231 }
 232
 233 } // namespace GiNaC