Description
This function returns the value of the arctangent of the point denoted by the x and y parameters. The return value is in radians, in the range -pi to pi (approximately -3.14 to 3.14). 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.
Syntax:
atan2(float $y, float $x): float
Parameters
| Parameter | Description |
|---|---|
| y | Dividend parameter |
| x | Divisor parameter |
Return Values
The arc tangent of y/x in radians.
Examples
Example 1:
Calculate the arctangent of a coordinate:
$tanx = -1; $tany = 1; echo "The arctangent of $tanx/$tany is ", atan2($tanx, $tany)