Implementation of arctan

This is the software implementation of the arctan function.

The code stretches over two pages.

phi = arctan2(y/x) // phi =< —π,π]. // Normally arcan gives phi =< —π/2,π/2] {
	if(y=>0)
	{
		if(x>0)
		{
			phi=arctan(y/x) //First Quadrant
		{
		elseif(x<0)
		{
			phi=π + arctan(y/x) //Second Quadrant
		}
		else
		{
			phi = π/2 //x=0, y=1)
		}
	}
	elseif(y<0)
	{
		if(x<0)
		{
			phi = —π + arctan(y/x) //Third Quadrant
		}
		elseif(x>0)
		{
			phi = arctan(y/x) //Fourth Quadrant
		}
		else
		{
			phi = —π/2 //(x=0, y=-1)
		}
	}
	else