ginac/fderivative.cpp

   1 /** @file fderivative.cpp
   2  *
   3  *  Implementation of abstract derivatives of functions. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2002 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 "print.h"
  27 #include "archive.h"
  28 #include "utils.h"
  29
  30 namespace GiNaC {
  31
  32 GINAC_IMPLEMENT_REGISTERED_CLASS(fderivative, function)
  33
  34 //////////
  35 // default ctor, dtor, copy ctor, assignment operator and helpers
  36 //////////
  37
  38 fderivative::fderivative()
  39 {
  40         tinfo_key = TINFO_fderivative;
  41 }
  42
  43 void fderivative::copy(const fderivative & other)
  44 {
  45         inherited::copy(other);
  46         parameter_set = other.parameter_set;
  47 }
  48
  49 DEFAULT_DESTROY(fderivative)
  50
  51 //////////
  52 // other constructors
  53 //////////
  54
  55 fderivative::fderivative(unsigned ser, unsigned param, const exvector & args) : function(ser, args)
  56 {
  57         parameter_set.insert(param);
  58         tinfo_key = TINFO_fderivative;
  59 }
  60
  61 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  62 {
  63         tinfo_key = TINFO_fderivative;
  64 }
  65
  66 fderivative::fderivative(unsigned ser, const paramset & params, exvector * vp) : function(ser, vp), parameter_set(params)
  67 {
  68         tinfo_key = TINFO_fderivative;
  69 }
  70
  71 //////////
  72 // archiving
  73 //////////
  74
  75 fderivative::fderivative(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
  76 {
  77         unsigned i = 0;
  78         while (true) {
  79                 unsigned u;
  80                 if (n.find_unsigned("param", u, i))
  81                         parameter_set.insert(u);
  82                 else
  83                         break;
  84                 ++i;
  85         }
  86 }
  87
  88 void fderivative::archive(archive_node &n) const
  89 {
  90         inherited::archive(n);
  91         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
  92         while (i != end) {
  93                 n.add_unsigned("param", *i);
  94                 ++i;
  95         }
  96 }
  97
  98 DEFAULT_UNARCHIVE(fderivative)
  99
 100 //////////
 101 // functions overriding virtual functions from base classes
 102 //////////
 103
 104 void fderivative::print(const print_context & c, unsigned level) const
 105 {
 106         if (is_a<print_tree>(c)) {
 107
 108                 c.s << std::string(level, ' ') << class_name() << " "
 109                     << registered_functions()[serial].name
 110                     << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 111                     << ", nops=" << nops()
 112                     << ", params=";
 113                 paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 114                 --end;
 115                 while (i != end)
 116                         c.s << *i++ << ",";
 117                 c.s << *i << std::endl;
 118                 unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
 119                 for (unsigned i=0; i<seq.size(); ++i)
 120                         seq[i].print(c, level + delta_indent);
 121                 c.s << std::string(level + delta_indent, ' ') << "=====" << std::endl;
 122
 123         } else {
 124
 125                 c.s << "D[";
 126                 paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 127                 --end;
 128                 while (i != end)
 129                         c.s << *i++ << ",";
 130                 c.s << *i << "](" << registered_functions()[serial].name << ")";
 131                 printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 132         }
 133 }
 134
 135 ex fderivative::eval(int level) const
 136 {
 137         if (level > 1) {
 138                 // first evaluate children, then we will end up here again
 139                 return fderivative(serial, parameter_set, evalchildren(level));
 140         }
 141
 142         // No parameters specified? Then return the function itself
 143         if (parameter_set.empty())
 144                 return function(serial, seq);
 145
 146         // If the function in question actually has a derivative, return it
 147         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 148                 return pderivative(*(parameter_set.begin()));
 149
 150         return this->hold();
 151 }
 152
 153 /** Numeric evaluation falls back to evaluation of arguments.
 154  *  @see basic::evalf */
 155 ex fderivative::evalf(int level) const
 156 {
 157         return basic::evalf(level);
 158 }
 159
 160 /** The series expansion of derivatives falls back to Taylor expansion.
 161  *  @see basic::series */
 162 ex fderivative::series(const relational & r, int order, unsigned options) const
 163 {
 164         return basic::series(r, order, options);
 165 }
 166
 167 ex fderivative::thisexprseq(const exvector & v) const
 168 {
 169         return fderivative(serial, parameter_set, v);
 170 }
 171
 172 ex fderivative::thisexprseq(exvector * vp) const
 173 {
 174         return fderivative(serial, parameter_set, vp);
 175 }
 176
 177 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 178  *  @see ex::diff */
 179 ex fderivative::derivative(const symbol & s) const
 180 {
 181         ex result;
 182         for (unsigned i=0; i!=seq.size(); i++) {
 183                 ex arg_diff = seq[i].diff(s);
 184                 if (!arg_diff.is_zero()) {
 185                         paramset ps = parameter_set;
 186                         ps.insert(i);
 187                         result += arg_diff * fderivative(serial, ps, seq);
 188                 }
 189         }
 190         return result;
 191 }
 192
 193 int fderivative::compare_same_type(const basic & other) const
 194 {
 195         GINAC_ASSERT(is_a<fderivative>(other));
 196         const fderivative & o = static_cast<const fderivative &>(other);
 197
 198         if (parameter_set != o.parameter_set)
 199                 return parameter_set < o.parameter_set ? -1 : 1;
 200         else
 201                 return inherited::compare_same_type(o);
 202 }
 203
 204 bool fderivative::is_equal_same_type(const basic & other) const
 205 {
 206         GINAC_ASSERT(is_a<fderivative>(other));
 207         const fderivative & o = static_cast<const fderivative &>(other);
 208
 209         if (parameter_set != o.parameter_set)
 210                 return false;
 211         else
 212                 return inherited::is_equal_same_type(o);
 213 }
 214
 215 bool fderivative::match_same_type(const basic & other) const
 216 {
 217         GINAC_ASSERT(is_a<fderivative>(other));
 218         const fderivative & o = static_cast<const fderivative &>(other);
 219
 220         return parameter_set == o.parameter_set;
 221 }
 222
 223 } // namespace GiNaC