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atan2

float atan2( float y, float x );

Description

Computes the arctangent of real float value y/x to find the angle in radians between the x-axis and the ray through (0,0) and (x,y).

NOTE	The Dynamic C functions deg and rad convert radians and degrees.

Parameters

y

The point corresponding to the y-axis

x

The point corresponding to the x-axis

Return value

If both y and x are zero, the function returns 0 and signals a domain error. Otherwise the arctangent of y/x is returned as follows:

Returned Value (in Radians)	Parameter Values
angle	x ≠ 0, y ≠ 0
PI/2	x = 0, y > 0
-PI/2	x = 0, y <
0	x > 0, y = 0
PI	x < 0, y = 0

Library

MATH.LIB

See also

acos, asin, atan, cos, sin, tan