i am a programmer and not a math guru, but i like geometry. so if i'm not accurate in math terminology or i have folly question please sorry me.
i'm drawing with a programming language the lissajous curve ( http://en.wikipedia.org/wiki/Lissajous_curve ), sampling 100 points.
i want to consider all segments formed by any two points. how can i understand if the segment is "inside" (i don't know how to explain it with right math words) the trigonometric curve?
here is an example:
the black segment is "outside", the blue one is "inside".
EDIT: - segment P1-P3 is considered "outside" - in wikipedia there is a general form but i consider only closed curve where a/b is rational