eigenmath/bessely.cpp

86 lines
1.0 KiB
C++

//-----------------------------------------------------------------------------
//
// Bessel Y function
//
// Input: tos-2 x (can be a symbol or expr)
//
// tos-1 n
//
// Output: Result on stack
//
//-----------------------------------------------------------------------------
#include "stdafx.h"
#include "defs.h"
void
eval_bessely(void)
{
push(cadr(p1));
eval();
push(caddr(p1));
eval();
bessely();
}
void
bessely(void)
{
save();
yybessely();
restore();
}
#define X p1
#define N p2
void
yybessely(void)
{
double d;
int n;
N = pop();
X = pop();
push(N);
n = pop_integer();
if (isdouble(X) && n != (int) 0x80000000) {
d = yn(n, X->u.d);
push_double(d);
return;
}
if (isnegativeterm(N)) {
push_integer(-1);
push(N);
power();
push_symbol(BESSELY);
push(X);
push(N);
negate();
list(3);
multiply();
return;
}
push_symbol(BESSELY);
push(X);
push(N);
list(3);
return;
}
static char *s[] = {
"bessely(x,n)",
"bessely(x,n)",
};
void
test_bessely(void)
{
test(__FILE__, s, sizeof s / sizeof (char *));
}