Humanizing atan2

April 27th, 2011

I’m sure everyone of you got livid with the return value of the atan2 functions. Here is a fix.

public double arctan (double x, double y)
{
	double d = Math.atan2 (x, y) % (2 * Math.PI);
	if (d >= 0 && d <= Math.PI / 2)
		return Math.PI / 2 - d;
	else if (d < 0 && d >= -Math.PI)
		return Math.PI / 2 - d;
	else if (d > Math.PI / 2 && d <= Math.PI)
		return 2.5 * Math.PI - d;
	return d;
}

This is Java code, but easy to adapt for other languages. And since you are here, a little hint: Multiply the result with 180 / Math.PI to receive the angle in degrees.

Martin Scharm

stuff. just for the records.

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