ginac/fderivative.cpp

   1 /** @file fderivative.cpp
   2  *
   3  *  Implementation of abstract derivatives of functions. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2001 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 "fderivative.h"
  24 #include "print.h"
  25 #include "archive.h"
  26 #include "utils.h"
  27
  28 namespace GiNaC {
  29
  30 GINAC_IMPLEMENT_REGISTERED_CLASS(fderivative, function)
  31
  32 //////////
  33 // default ctor, dtor, copy ctor, assignment operator and helpers
  34 //////////
  35
  36 fderivative::fderivative()
  37 {
  38         tinfo_key = TINFO_fderivative;
  39 }
  40
  41 void fderivative::copy(const fderivative & other)
  42 {
  43         inherited::copy(other);
  44         parameter_set = other.parameter_set;
  45 }
  46
  47 DEFAULT_DESTROY(fderivative)
  48
  49 //////////
  50 // other constructors
  51 //////////
  52
  53 fderivative::fderivative(unsigned ser, unsigned param, const exvector & args) : function(ser, args)
  54 {
  55         parameter_set.insert(param);
  56         tinfo_key = TINFO_fderivative;
  57 }
  58
  59 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  60 {
  61         tinfo_key = TINFO_fderivative;
  62 }
  63
  64 fderivative::fderivative(unsigned ser, const paramset & params, exvector * vp) : function(ser, vp), parameter_set(params)
  65 {
  66         tinfo_key = TINFO_fderivative;
  67 }
  68
  69 //////////
  70 // archiving
  71 //////////
  72
  73 fderivative::fderivative(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
  74 {
  75         unsigned i = 0;
  76         while (true) {
  77                 unsigned u;
  78                 if (n.find_unsigned("param", u, i))
  79                         parameter_set.insert(u);
  80                 else
  81                         break;
  82                 ++i;
  83         }
  84 }
  85
  86 void fderivative::archive(archive_node &n) const
  87 {
  88         inherited::archive(n);
  89         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
  90         while (i != end) {
  91                 n.add_unsigned("param", *i);
  92                 ++i;
  93         }
  94 }
  95
  96 DEFAULT_UNARCHIVE(fderivative)
  97
  98 //////////
  99 // functions overriding virtual functions from base classes
 100 //////////
 101
 102 void fderivative::print(const print_context & c, unsigned level) const
 103 {
 104         if (is_a<print_tree>(c)) {
 105
 106                 c.s << std::string(level, ' ') << class_name() << " "
 107                     << registered_functions()[serial].name
 108                     << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 109                     << ", nops=" << nops()
 110                     << ", params=";
 111                 paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 112                 --end;
 113                 while (i != end)
 114                         c.s << *i++ << ",";
 115                 c.s << *i << std::endl;
 116                 unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
 117                 for (unsigned i=0; i<seq.size(); ++i)
 118                         seq[i].print(c, level + delta_indent);
 119                 c.s << std::string(level + delta_indent, ' ') << "=====" << std::endl;
 120
 121         } else {
 122
 123                 c.s << "D[";
 124                 paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 125                 --end;
 126                 while (i != end)
 127                         c.s << *i++ << ",";
 128                 c.s << *i << "](" << registered_functions()[serial].name << ")";
 129                 printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 130         }
 131 }
 132
 133 ex fderivative::eval(int level) const
 134 {
 135         if (level > 1) {
 136                 // first evaluate children, then we will end up here again
 137                 return fderivative(serial, parameter_set, evalchildren(level));
 138         }
 139
 140         // No parameters specified? Then return the function itself
 141         if (parameter_set.empty())
 142                 return function(serial, seq);
 143
 144         // If the function in question actually has a derivative, return it
 145         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 146                 return pderivative(*(parameter_set.begin()));
 147
 148         return this->hold();
 149 }
 150
 151 /** Numeric evaluation falls back to evaluation of arguments.
 152  *  @see basic::evalf */
 153 ex fderivative::evalf(int level) const
 154 {
 155         return basic::evalf(level);
 156 }
 157
 158 /** The series expansion of derivatives falls back to Taylor expansion.
 159  *  @see basic::series */
 160 ex fderivative::series(const relational & r, int order, unsigned options) const
 161 {
 162         return basic::series(r, order, options);
 163 }
 164
 165 ex fderivative::thisexprseq(const exvector & v) const
 166 {
 167         return fderivative(serial, parameter_set, v);
 168 }
 169
 170 ex fderivative::thisexprseq(exvector * vp) const
 171 {
 172         return fderivative(serial, parameter_set, vp);
 173 }
 174
 175 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 176  *  @see ex::diff */
 177 ex fderivative::derivative(const symbol & s) const
 178 {
 179         ex result;
 180         for (unsigned i=0; i!=seq.size(); i++) {
 181                 ex arg_diff = seq[i].diff(s);
 182                 if (!arg_diff.is_zero()) {
 183                         paramset ps = parameter_set;
 184                         ps.insert(i);
 185                         result += arg_diff * fderivative(serial, ps, seq);
 186                 }
 187         }
 188         return result;
 189 }
 190
 191 int fderivative::compare_same_type(const basic & other) const
 192 {
 193         GINAC_ASSERT(is_a<fderivative>(other));
 194         const fderivative & o = static_cast<const fderivative &>(other);
 195
 196         if (parameter_set != o.parameter_set)
 197                 return parameter_set < o.parameter_set ? -1 : 1;
 198         else
 199                 return inherited::compare_same_type(o);
 200 }
 201
 202 bool fderivative::is_equal_same_type(const basic & other) const
 203 {
 204         GINAC_ASSERT(is_a<fderivative>(other));
 205         const fderivative & o = static_cast<const fderivative &>(other);
 206
 207         if (parameter_set != o.parameter_set)
 208                 return false;
 209         else
 210                 return inherited::is_equal_same_type(o);
 211 }
 212
 213 bool fderivative::match_same_type(const basic & other) const
 214 {
 215         GINAC_ASSERT(is_a<fderivative>(other));
 216         const fderivative & o = static_cast<const fderivative &>(other);
 217
 218         return parameter_set == o.parameter_set;
 219 }
 220
 221 } // namespace GiNaC