Eigenmath/cosh.cpp

47 lines
543 B
C++

// exp(x) + exp(-x)
// cosh(x) = ----------------
// 2
#include "stdafx.h"
#include "defs.h"
void
eval_cosh(void)
{
push(cadr(p1));
eval();
ycosh();
}
void
ycosh(void)
{
save();
yycosh();
restore();
}
void
yycosh(void)
{
double d;
p1 = pop();
if (car(p1) == symbol(ARCCOSH)) {
push(cadr(p1));
return;
}
if (isdouble(p1)) {
d = cosh(p1->u.d);
if (fabs(d) < 1e-10)
d = 0.0;
push_double(d);
return;
}
if (iszero(p1)) {
push(one);
return;
}
push_symbol(COSH);
push(p1);
list(2);
}