eigenmath/sinh.cpp
George Weigt 458f8c69db edit
2006-01-03 18:21:32 -07:00

78 lines
860 B
C++

// exp(x) - exp(-x)
// sinh(x) = ----------------
// 2
#include "stdafx.h"
#include "defs.h"
void
eval_sinh(void)
{
push(cadr(p1));
eval();
ysinh();
}
void
ysinh(void)
{
save();
yysinh();
restore();
}
void
yysinh(void)
{
double d;
p1 = pop();
if (isdouble(p1)) {
d = sinh(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();
subtract();
push_rational(1, 2);
multiply();
return;
}
if (iszero(p1)) {
push(zero);
return;
}
push_symbol(SINH);
push(p1);
list(2);
}
static char *s[] = {
"sinh(x)",
"sinh(x)",
"sinh(0)",
"0",
"expomode=1",
"",
"sinh(x)",
"1/2*exp(x)-1/2*exp(-x)",
"expomode=0",
"",
};
void
test_sinh(void)
{
test(__FILE__, s, sizeof s / sizeof (char *));
}