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ATAN2(3) | Linux Programmer's Manual | ATAN2(3) |
NAME¶
atan2, atan2f, atan2l - arc tangent function of two variablesSYNOPSIS¶
#include <math.h> double atan2(double y, double x); float atan2f(float y, float x); long double atan2l(long double y, long double x);Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE ||
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION¶
The atan2() function calculates the principal value of the arc tangent of y/x, using the signs of the two arguments to determine the quadrant of the result.RETURN VALUE¶
On success, these functions return the principal value of the arc tangent of y/x in radians; the return value is in the range [-pi, pi].ERRORS¶
No errors occur.CONFORMING TO¶
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.SEE ALSO¶
acos(3), asin(3), atan(3), carg(3), cos(3), sin(3), tan(3)COLOPHON¶
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.2010-09-20 |