Add LaTeX pretty-print for function derivatives.
[ginac.git] / ginac / fderivative.cpp
1 /** @file fderivative.cpp
2  *
3  *  Implementation of abstract derivatives of functions. */
4
5 /*
6  *  GiNaC Copyright (C) 1999-2017 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_latex>(&fderivative::do_print_latex).
35   print_func<print_csrc>(&fderivative::do_print_csrc).
36   print_func<print_tree>(&fderivative::do_print_tree))
37
38 //////////
39 // default constructor
40 //////////
41
42 fderivative::fderivative()
43 {
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 }
54
55 fderivative::fderivative(unsigned ser, const paramset & params, const exvector & args) : function(ser, args), parameter_set(params)
56 {
57 }
58
59 fderivative::fderivative(unsigned ser, const paramset & params, exvector && v) : function(ser, std::move(v)), parameter_set(params)
60 {
61 }
62
63 //////////
64 // archiving
65 //////////
66
67 void fderivative::read_archive(const archive_node& n, lst& sym_lst)
68 {
69         inherited::read_archive(n, sym_lst);
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 GINAC_BIND_UNARCHIVER(fderivative);
81
82 void fderivative::archive(archive_node &n) const
83 {
84         inherited::archive(n);
85         auto i = parameter_set.begin(), end = parameter_set.end();
86         while (i != end) {
87                 n.add_unsigned("param", *i);
88                 ++i;
89         }
90 }
91
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         // class function overrides print(), but we don't want that
100         basic::print(c, level);
101 }
102
103 void fderivative::do_print(const print_context & c, unsigned level) const
104 {
105         c.s << "D[";
106         auto i = parameter_set.begin(), end = parameter_set.end();
107         --end;
108         while (i != end) {
109                 c.s << *i++ << ",";
110         }
111         c.s << *i << "](" << registered_functions()[serial].name << ")";
112         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
113 }
114
115 void fderivative::do_print_latex(const print_context & c, unsigned level) const
116 {
117         int order=1;
118         c.s << "\\partial_{";
119         auto i = parameter_set.begin(), end = parameter_set.end();
120         --end;
121         while (i != end) {
122                 ++order;
123                 c.s << *i++ << ",";
124         }
125         c.s << *i << "}";
126         if (order>1)
127                 c.s << "^{" << order << "}";
128         c.s << "(" << registered_functions()[serial].TeX_name << ")";
129         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
130 }
131
132 void fderivative::do_print_csrc(const print_csrc & c, unsigned level) const
133 {
134         c.s << "D_";
135         auto i = parameter_set.begin(), end = parameter_set.end();
136         --end;
137         while (i != end)
138                 c.s << *i++ << "_";
139         c.s << *i << "_" << registered_functions()[serial].name;
140         printseq(c, '(', ',', ')', exprseq::precedence(), function::precedence());
141 }
142
143 void fderivative::do_print_tree(const print_tree & c, unsigned level) const
144 {
145         c.s << std::string(level, ' ') << class_name() << " "
146             << registered_functions()[serial].name << " @" << this
147             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
148             << ", nops=" << nops()
149             << ", params=";
150         auto i = parameter_set.begin(), end = parameter_set.end();
151         --end;
152         while (i != end)
153                 c.s << *i++ << ",";
154         c.s << *i << std::endl;
155         for (auto & i : seq)
156                 i.print(c, level + c.delta_indent);
157         c.s << std::string(level + c.delta_indent, ' ') << "=====" << std::endl;
158 }
159
160 ex fderivative::eval() const
161 {
162         // No parameters specified? Then return the function itself
163         if (parameter_set.empty())
164                 return function(serial, seq);
165
166         // If the function in question actually has a derivative, return it
167         if (registered_functions()[serial].has_derivative() && parameter_set.size() == 1)
168                 return pderivative(*(parameter_set.begin()));
169
170         return this->hold();
171 }
172
173 /** The series expansion of derivatives falls back to Taylor expansion.
174  *  @see basic::series */
175 ex fderivative::series(const relational & r, int order, unsigned options) const
176 {
177         return basic::series(r, order, options);
178 }
179
180 ex fderivative::thiscontainer(const exvector & v) const
181 {
182         return fderivative(serial, parameter_set, v);
183 }
184
185 ex fderivative::thiscontainer(exvector && v) const
186 {
187         return fderivative(serial, parameter_set, std::move(v));
188 }
189
190 /** Implementation of ex::diff() for derivatives. It applies the chain rule.
191  *  @see ex::diff */
192 ex fderivative::derivative(const symbol & s) const
193 {
194         ex result;
195         for (size_t i=0; i<seq.size(); i++) {
196                 ex arg_diff = seq[i].diff(s);
197                 if (!arg_diff.is_zero()) {
198                         paramset ps = parameter_set;
199                         ps.insert(i);
200                         result += arg_diff * fderivative(serial, ps, seq);
201                 }
202         }
203         return result;
204 }
205
206 int fderivative::compare_same_type(const basic & other) const
207 {
208         GINAC_ASSERT(is_a<fderivative>(other));
209         const fderivative & o = static_cast<const fderivative &>(other);
210
211         if (parameter_set != o.parameter_set)
212                 return parameter_set < o.parameter_set ? -1 : 1;
213         else
214                 return inherited::compare_same_type(o);
215 }
216
217 bool fderivative::is_equal_same_type(const basic & other) const
218 {
219         GINAC_ASSERT(is_a<fderivative>(other));
220         const fderivative & o = static_cast<const fderivative &>(other);
221
222         if (parameter_set != o.parameter_set)
223                 return false;
224         else
225                 return inherited::is_equal_same_type(o);
226 }
227
228 bool fderivative::match_same_type(const basic & other) const
229 {
230         GINAC_ASSERT(is_a<fderivative>(other));
231         const fderivative & o = static_cast<const fderivative &>(other);
232
233         return parameter_set == o.parameter_set && inherited::match_same_type(other);
234 }
235
236 /** Expose this object's derivative structure.
237  *
238  *  Parameter numbers occurring more than once stand for repeated
239  *  differentiation with respect to that parameter. If a symbolic function
240  *  f(x,y) is differentiated with respect to x, this method will return {0}.
241  *  If f(x,y) is differentiated twice with respect to y, it will return {1,1}.
242  *  (This corresponds to the way this object is printed.)
243  *
244  *  @return  multiset of function's parameter numbers that are abstractly
245  *  differentiated. */
246 const paramset& fderivative::derivatives() const
247 {
248         return parameter_set;
249 }
250
251
252 } // namespace GiNaC