GNU/Linux |
CentOS 5.3 |
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atan2l(3) |
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atan2, atan2f, atan2l − arc tangent function of two variables
#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.
The atan2() function calculates the arc tangent of the two variables x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result.
The atan2() function returns the result in radians, which is between −PI and PI (inclusive).
SVr4, POSIX.1-2001, 4.3BSD, C89. The float and long double variants are C99 requirements.
acos(3), asin(3), atan(3), cos(3), sin(3), tan(3)
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atan2l(3) | ![]() |