ginac/fderivative.cpp

   1 /** @file fderivative.cpp
   2  *
   3  *  Implementation of abstract derivatives of functions. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2011 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 "fderivative.h"
  24 #include "operators.h"
  25 #include "archive.h"
  26 #include "utils.h"
  27
  28 #include <iostream>
  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 }
  44
  45 //////////
  46 // other constructors
  47 //////////
  48
  49 fderivative::fderivative(unsigned ser, unsigned param, const exvector & args) : function(ser, args)
  50 {
  51         parameter_set.insert(param);
  52 }
  53
  54 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
  55 {
  56 }
  57
  58 fderivative::fderivative(unsigned ser, const paramset & params, std::auto_ptr<exvector> vp) : function(ser, vp), parameter_set(params)
  59 {
  60 }
  61
  62 //////////
  63 // archiving
  64 //////////
  65
  66 void fderivative::read_archive(const archive_node& n, lst& sym_lst)
  67 {
  68         inherited::read_archive(n, sym_lst);
  69         unsigned i = 0;
  70         while (true) {
  71                 unsigned u;
  72                 if (n.find_unsigned("param", u, i))
  73                         parameter_set.insert(u);
  74                 else
  75                         break;
  76                 ++i;
  77         }
  78 }
  79 GINAC_BIND_UNARCHIVER(fderivative);
  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
  92 //////////
  93 // functions overriding virtual functions from base classes
  94 //////////
  95
  96 void fderivative::print(const print_context & c, unsigned level) const
  97 {
  98         // class function overrides print(), but we don't want that
  99         basic::print(c, level);
 100 }
 101
 102 void fderivative::do_print(const print_context & c, unsigned level) const
 103 {
 104         c.s << "D[";
 105         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 106         --end;
 107         while (i != end) {
 108                 c.s << *i++ << ",";
 109         }
 110         c.s << *i << "](" << registered_functions()[serial].name << ")";
 111         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 112 }
 113
 114 void fderivative::do_print_csrc(const print_csrc & c, unsigned level) const
 115 {
 116         c.s << "D_";
 117         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 118         --end;
 119         while (i != end)
 120                 c.s << *i++ << "_";
 121         c.s << *i << "_" << registered_functions()[serial].name;
 122         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
 123 }
 124
 125 void fderivative::do_print_tree(const print_tree & c, unsigned level) const
 126 {
 127         c.s << std::string(level, ' ') << class_name() << " "
 128             << registered_functions()[serial].name << " @" << this
 129             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 130             << ", nops=" << nops()
 131             << ", params=";
 132         paramset::const_iterator i = parameter_set.begin(), end = parameter_set.end();
 133         --end;
 134         while (i != end)
 135                 c.s << *i++ << ",";
 136         c.s << *i << std::endl;
 137         for (size_t i=0; i<seq.size(); ++i)
 138                 seq[i].print(c, level + c.delta_indent);
 139         c.s << std::string(level + c.delta_indent, ' ') << "=====" << std::endl;
 140 }
 141
 142 ex fderivative::eval(int level) const
 143 {
 144         if (level > 1) {
 145                 // first evaluate children, then we will end up here again
 146                 return fderivative(serial, parameter_set, evalchildren(level));
 147         }
 148
 149         // No parameters specified? Then return the function itself
 150         if (parameter_set.empty())
 151                 return function(serial, seq);
 152
 153         // If the function in question actually has a derivative, return it
 154         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
 155                 return pderivative(*(parameter_set.begin()));
 156
 157         return this->hold();
 158 }
 159
 160 /** Numeric evaluation falls back to evaluation of arguments.
 161  *  @see basic::evalf */
 162 ex fderivative::evalf(int level) const
 163 {
 164         return basic::evalf(level);
 165 }
 166
 167 /** The series expansion of derivatives falls back to Taylor expansion.
 168  *  @see basic::series */
 169 ex fderivative::series(const relational & r, int order, unsigned options) const
 170 {
 171         return basic::series(r, order, options);
 172 }
 173
 174 ex fderivative::thiscontainer(const exvector & v) const
 175 {
 176         return fderivative(serial, parameter_set, v);
 177 }
 178
 179 ex fderivative::thiscontainer(std::auto_ptr<exvector> vp) const
 180 {
 181         return fderivative(serial, parameter_set, vp);
 182 }
 183
 184 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
 185  *  @see ex::diff */
 186 ex fderivative::derivative(const symbol & s) const
 187 {
 188         ex result;
 189         for (size_t i=0; i<seq.size(); i++) {
 190                 ex arg_diff = seq[i].diff(s);
 191                 if (!arg_diff.is_zero()) {
 192                         paramset ps = parameter_set;
 193                         ps.insert(i);
 194                         result += arg_diff * fderivative(serial, ps, seq);
 195                 }
 196         }
 197         return result;
 198 }
 199
 200 int fderivative::compare_same_type(const basic & other) const
 201 {
 202         GINAC_ASSERT(is_a<fderivative>(other));
 203         const fderivative & o = static_cast<const fderivative &>(other);
 204
 205         if (parameter_set != o.parameter_set)
 206                 return parameter_set < o.parameter_set ? -1 : 1;
 207         else
 208                 return inherited::compare_same_type(o);
 209 }
 210
 211 bool fderivative::is_equal_same_type(const basic & other) const
 212 {
 213         GINAC_ASSERT(is_a<fderivative>(other));
 214         const fderivative & o = static_cast<const fderivative &>(other);
 215
 216         if (parameter_set != o.parameter_set)
 217                 return false;
 218         else
 219                 return inherited::is_equal_same_type(o);
 220 }
 221
 222 bool fderivative::match_same_type(const basic & other) const
 223 {
 224         GINAC_ASSERT(is_a<fderivative>(other));
 225         const fderivative & o = static_cast<const fderivative &>(other);
 226
 227         return parameter_set == o.parameter_set && inherited::match_same_type(other);
 228 }
 229
 230 } // namespace GiNaC