85 lines
1.0 KiB
C++
85 lines
1.0 KiB
C++
|
//-----------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// exp(x) + exp(-x)
|
||
|
|
// cosh(x) = ----------------
|
||
|
|
// 2
|
||
|
|
//
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
|
||
|
|
#include "stdafx.h"
|
||
|
|
#include "defs.h"
|
||
|
|
void ycosh(void);
|
||
|
|
static void yycosh(void);
|
||
|
|
|
||
|
|
void
|
||
|
|
eval_cosh(void)
|
||
|
|
{
|
||
|
|
push(cadr(p1));
|
||
|
|
eval();
|
||
|
|
ycosh();
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
ycosh(void)
|
||
|
|
{
|
||
|
|
save();
|
||
|
|
yycosh();
|
||
|
|
restore();
|
||
|
|
}
|
||
|
|
|
||
|
|
static void
|
||
|
|
yycosh(void)
|
||
|
|
{
|
||
|
|
double d;
|
||
|
|
p1 = pop();
|
||
|
|
if (p1->k == DOUBLE) {
|
||
|
|
d = cosh(p1->u.d);
|
||
|
|
if (fabs(d) < 1e-10)
|
||
|
|
d = 0.0;
|
||
|
|
push_double(d);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (expomode == 1) {
|
||
|
|
push(p1);
|
||
|
|
exponential();
|
||
|
|
push(p1);
|
||
|
|
negate();
|
||
|
|
exponential();
|
||
|
|
add();
|
||
|
|
push_rational(1, 2);
|
||
|
|
multiply();
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (iszero(p1)) {
|
||
|
|
push(_one);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
push_symbol(COSH);
|
||
|
|
push(p1);
|
||
|
|
list(2);
|
||
|
|
}
|
||
|
|
|
||
|
|
static char *s[] = {
|
||
|
|
|
||
|
|
"cosh(x)",
|
||
|
|
"cosh(x)",
|
||
|
|
|
||
|
|
"cosh(0)",
|
||
|
|
"1",
|
||
|
|
|
||
|
|
"expomode=1",
|
||
|
|
"",
|
||
|
|
|
||
|
|
"cosh(x)",
|
||
|
|
"1/2*exp(x)+1/2*exp(-x)",
|
||
|
|
|
||
|
|
"expomode=0",
|
||
|
|
"",
|
||
|
|
};
|
||
|
|
|
||
|
|
void
|
||
|
|
test_cosh(void)
|
||
|
|
{
|
||
|
|
test(__FILE__, s, sizeof s / sizeof (char *));
|
||
|
|
}
|