1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
/*
function.cc, copyright (c) 2006 by Vincent Fourmond:
The implementation of (all) functions.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details (in the COPYING file).
*/
#include <calc_internals.hh>
// the functions we want ;-) !!!!
#include <math.h>
namespace SCalc {
std::string FuncDef::pretty_print()
{
return std::string("biniou");
}
int FuncDef::register_self()
{
if(name().empty())
return 0; // will fail anyway
return session()->register_func_def(this);
}
CFunc::CFunc(Session * s, const char * n,
c_function_t f,
FuncDef * d) : FuncDef(s, 1)
{
deriv = d;
func = f;
set_name(n);
register_self();
}
double CFunc::evaluate(const double * vars, const double * args)
{
return func(*args); // simple, isn't it ?
}
// The heavyside function, to allow for conditional stuff.
static double heavy(double arg)
{
if(arg >= 0)
return 1.0;
else
return 0;
}
// This function registers a whole bunch of common functions for the
// session to use.
void FuncDef::register_common_functions(Session * s)
{
CFunc * def;
CFunc * def2;
// hyperbolic functions
def = new CFunc(s, "exp", exp);
def->set_derivative(def); // cool, isn't it ???
def = new CFunc(s, "ln", log);
def->set_derivative(s->eval("x->1/x")
->to_func_def());
// trigonometric functions
def = new CFunc(s, "sin", sin);
def2 = new CFunc(s, "cos", cos);
def->set_derivative(def2);
def2->set_derivative(s->eval("x->-sin(x)")
->to_func_def());
def = new CFunc(s, "tan", tan);
def->set_derivative(s->eval("x->1 + tan(x)^2")
->to_func_def());
// Define sqrt before using it...
def = new CFunc(s, "sqrt", sqrt);
def->set_derivative(s->eval("x->0.5*x**(-0.5)")
->to_func_def());
// reverse trigonometric functions
def = new CFunc(s, "asin", asin);
def->set_derivative(s->eval("x->1/sqrt(1 - x**2)")
->to_func_def());
def = new CFunc(s, "acos", acos);
def->set_derivative(s->eval("x->-1/sqrt(1 - x**2)")
->to_func_def());
def = new CFunc(s, "atan", atan);
def->set_derivative(s->eval("x->1/(1 + x**2)")
->to_func_def());
// Common hyperbolic functions
def = new CFunc(s, "cosh", cosh);
def2 = new CFunc(s, "sinh", sinh);
// The most easy derivates, and the most elegant as well
def2->set_derivative(def);
def->set_derivative(def2);
// def->set_derivative(s->eval("x->sinh(x")
// ->to_func_def());
def = new CFunc(s, "tanh", tanh);
def->set_derivative(s->eval("x->1/(cosh(x)**2)")
->to_func_def());
def = new CFunc(s, "erf", erf);
def->set_derivative(s->eval("x->exp(-x**2)")
->to_func_def());
def = new CFunc(s, "gamma", tgamma);
/* no simple derivative that I know of ... */
// The heavyside function - to allow conditional behavior
// Do not derive !!
def = new CFunc(s, "heavy", heavy);
}
void CFunc::destroy_anonymous_derivatives()
{
if(deriv && deriv->name().empty())
{
delete deriv;
deriv = NULL;
}
}
void ExprFunc::destroy_anonymous_derivatives()
{
for(std::map<int, FuncDef*>::iterator i =
cached_derivatives.begin();
i != cached_derivatives.end(); i++)
{
FuncDef * f = i->second;
if(f->name().empty())
delete f;
}
}
FuncDef * ExprFunc::derivative(int nb)
{
std::map<int, FuncDef*>::iterator i = cached_derivatives.find(nb);
if(i != cached_derivatives.end())
return i->second;
FuncDef * func = new ExprFunc(session(),
exp->derive(-(nb+1)),
nb_params());
cached_derivatives[nb] = func;
return func;
}
std::string ExprFunc::pretty_print()
{
std::string str = "fundef: ";
str += exp->pretty_print();
return str;
}
CFuncParam::CFuncParam(Session * s, const char * n,
c_function_t f, void * p,
FuncDef * d) : CFunc(s, n, NULL, d)
{
func = f;
_param = p;
}
double CFuncParam::evaluate(const double * vars, const double * args)
{
return func(_param, *args); // simple, isn't it ?
}
};
|
