eigenmath/tan.cpp

220 lines
2.4 KiB
C++

#include "stdafx.h"
#include "defs.h"
static void __tangent(void);
void
eval_tan(void)
{
push(cadr(p1));
eval();
tangent();
}
void
tangent(void)
{
save();
__tangent();
restore();
}
static void
__tangent(void)
{
int n;
double d;
p1 = pop();
if (p1->k == DOUBLE) {
d = tan(p1->u.d);
if (fabs(d) < 1e-10)
d = 0.0;
push_double(d);
return;
}
if (expomode == 1) {
push(unit_imaginary);
push(p1);
multiply();
exponential();
p2 = pop();
push(unit_imaginary);
push(p1);
multiply();
negate();
exponential();
p3 = pop();
push(p3);
push(p2);
subtract();
push(unit_imaginary);
multiply();
push(p2);
push(p3);
add();
divide();
return;
}
// multiply by 180/pi
push(p1);
push_integer(180);
multiply();
push_symbol(PI);
divide();
n = pop_integer();
if (n == (int) 0x80000000) {
push_symbol(TAN);
push(p1);
list(2);
return;
}
switch(n % 360) {
case -315:
push_integer(1);
break;
case -225:
push_integer(-1);
break;
case -180:
push_integer(0);
break;
case -135:
push_integer(1);
break;
case -45:
push_integer(-1);
break;
case 0:
push_integer(0);
break;
case 45:
push_integer(1);
break;
case 135:
push_integer(-1);
break;
case 180:
push_integer(0);
break;
case 225:
push_integer(1);
break;
case 315:
push_integer(-1);
break;
default:
push_symbol(TAN);
push(p1);
list(2);
break;
}
}
static char *s[] = {
"tan(x)",
"tan(x)",
"tan(-2 pi)",
"0",
"tan(-7 pi/4)",
"1",
"tan(-5 pi/4)",
"-1",
"tan(-pi)",
"0",
"tan(-3 pi/4)",
"1",
"tan(-pi/4)",
"-1",
"tan(0)",
"0",
"tan(pi/4)",
"1",
"tan(3 pi/4)",
"-1",
"tan(pi)",
"0",
"tan(5 pi/4)",
"1",
"tan(7 pi/4)",
"-1",
"tan(2 pi)",
"0",
"tan(-2 pi)+tan(float(-2 pi))",
"0",
"tan(-7 pi/4)+tan(float(-7 pi/4))",
"2",
"tan(-5 pi/4)+tan(float(-5 pi/4))",
"-2",
"tan(-pi)+tan(float(-pi))",
"0",
"tan(-3 pi/4)+tan(float(-3 pi/4))",
"2",
"tan(-pi/4)+tan(float(-pi/4))",
"-2",
"tan(0)+tan(0.0)",
"0",
"tan(pi/4)+tan(float(pi/4))",
"2",
"tan(3 pi/4)+tan(float(3 pi/4))",
"-2",
"tan(pi)+tan(float(pi))",
"0",
"tan(5 pi/4)+tan(float(5 pi/4))",
"2",
"tan(7 pi/4)+tan(float(7 pi/4))",
"-2",
"tan(2 pi)+tan(float(2 pi))",
"0",
"expomode=1",
"",
"tan(x)",
"i*exp(-i*x)/(exp(-i*x)+exp(i*x))-i*exp(i*x)/(exp(-i*x)+exp(i*x))",
"expomode=0",
"",
};
void
test_tan(void)
{
test(__FILE__, s, sizeof s / sizeof (char *));
}