PHP atan2() Function
Example
Return the arc tangent of two variables with the atan2() function:
<?php
echo(atan2(0.50,0.50) . "<br>");
echo(atan2(-0.50,-0.50) . "<br>");
echo(atan2(5,5) . "<br>");
echo(atan2(10,20) . "<br>");
echo(atan2(-5,-5) . "<br>");
echo(atan2(-10,10));
?>
Try it Yourself »
Definition and Usage
The atan2() function returns the arc tangent of y/x, in radians. Where x and y are the coordinates of a point (x,y).
Syntax
atan2(y,x);
Parameter Values
| Parameter | Description |
|---|---|
| y | Required. Specifies a positive or negative number |
| x | Required. Specifies a positive or negative number |
Technical Details
| Return Value: | The arc tangent of y/x in radians, which is between -PI and PI |
|---|---|
| Return Type: | Float |
| PHP Version: | 4+ |
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