eigenmath/arctanh.cpp

55 lines
680 B
C++

#include "stdafx.h"
#include "defs.h"
static void arctanh(void);
void
eval_arctanh(void)
{
push(cadr(p1));
eval();
arctanh();
}
static void
arctanh(void)
{
double d;
save();
p1 = pop();
if (p1->k == DOUBLE) {
d = p1->u.d;
if (d < -1.0 || d > 1.0)
stop("arctanh function argument is not in the interval [-1,1]");
d = log((1.0 + d) / (1.0 - d)) / 2.0;
push_double(d);
restore();
return;
}
if (iszero(p1)) {
push(_zero);
restore();
return;
}
push_symbol(ARCTANH);
push(p1);
list(2);
restore();
}
static char *s[] = {
"arctanh(0.0)",
"0",
"arctanh(0)",
"0",
};
void
test_arctanh(void)
{
test(__FILE__, s, sizeof s / sizeof (char *));
}