atan2

atan2 - Arc tangent of two variables

float atan2 ( float $x, $y )

This 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 function returns the result in radians, which is between -PI and PI (inclusive).

Parameters:

x - The denominator. It can be a scalar or an array.

y - The nominator. It can be a scalar or an array.

Return Value:

The arc tangent of y / x in radians. If x or y is an array, the return value will also be an array, the size of which matches the larger of x and y.

Version

1.0 and above.