Ellipse trouble

[dcromley]

James,

Solving the equation for x is the easy part:
x^2/a^2 + y^2/b^2 = 1
x^2/a^2 = 1 - y^2/b^2
x^2 = (1 - y^2/b^2 )*a^2
x = +sqr((1 - y^2/b^2 )*a^2)
and
x = -sqr((1 - y^2/b^2 )*a^2)
if I haven't made a mistake.

But you can use CIRCLE to draw ellipses.  Or, if you are into self-flagellation, there are algorithms using PSET.

Here is a start using CIRCLE (the ASPECT parameter!):

Code: (Select All)

Screen _NewImage(1024, 768, 256)
Cls 0, 15
Color 0, 15

Circle (512, 384), 200
Circle (512, 384), 100
Circle (512, 384), 200, 9, , , 2 ' blue
Circle (512, 384), 200, 10, , , .5 ' green