Warning: Attempt to read property "date" on null in /usr/local/www/websvn.planix.org/blame.php on line 247

Warning: Attempt to read property "msg" on null in /usr/local/www/websvn.planix.org/blame.php on line 247
WebSVN – planix.SVN – Blame – /os/branches/feature_tlsv12/sys/src/ape/lib/ap/math/asin.c – Rev 2

Subversion Repositories planix.SVN

Rev

Go to most recent revision | Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
/*
2 
	asin(arg) and acos(arg) return the arcsin, arccos,
3 
	respectively of their arguments.
4 
 
5 
	Arctan is called after appropriate range reduction.
6 
 */
7 
 
8 
#include <math.h>
9 
#include <errno.h>
10 
 
11 
static double pio2	= 1.570796326794896619231e0;
12 
 
13 
double
14 
asin(double arg)
15 
{
16 
	double temp;
17 
	int sign;
18 
 
19 
	sign = 0;
20 
	if(arg < 0) {
21 
		arg = -arg;
22 
		sign++;
23 
	}
24 
	if(arg > 1) {
25 
		errno = EDOM;
26 
		return 0;
27 
	}
28 
	temp = sqrt(1 - arg*arg);
29 
	if(arg > 0.7)
30 
		temp = pio2 - atan(temp/arg);
31 
	else
32 
		temp = atan(arg/temp);
33 
 
34 
	if(sign)
35 
		temp = -temp;
36 
	return temp;
37 
}
38 
 
39 
double
40 
acos(double arg)
41 
{
42 
	if(arg > 1 || arg < -1) {
43 
		errno = EDOM;
44 
		return 0;
45 
	}
46 
	return pio2 - asin(arg);
47 
}