#atan

return the arc-tangent of the parameters

#Declaration

• float atan(float x)
• vec2 atan(vec2 x)
• vec3 atan(vec3 x)
• vec4 atan(vec4 x)
• float atan(float y, float x)
• vec2 atan(vec2 y, vec2 x)
• vec3 atan(vec3 y, vec3 x)
• vec4 atan(vec4 y, vec4 x)

#Parameters

• y: Specify the numerator of the fraction whose arctangent to return.
• x: Specify the denominator of the fraction whose arctangent to return.
• y_over_x: Specify the fraction whose arctangent to return.

#Description

atan returns the angle whose trigonometric arctangent is $$ \frac{y}{x} $$ or 𝑦_𝑜𝑣𝑒𝑟_𝑥, depending on which overload is invoked. In the first overload, the signs of 𝑦 and 𝑥 are used to determine the quadrant that the angle lies in. The values returned by atan in this case are in the range [−𝜋,𝜋]. Results are undefined if 𝑥 is zero. For the second overload, atan returns the angle whose tangent is 𝑦_𝑜𝑣𝑒𝑟_𝑥. Values returned in this case are in the range $$ \left[ -\frac{\pi}{2}, \frac{\pi}{2} \right] $$

#See Also

• sin
• cos
• tan
• asin
• acos