Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Dear IDL users, If I have 4 random points (x0,y0) (x1,y1), (x3,y3), (x4,y4), is there a simple way to decide whether one of them is inside of the triangle formed by the other three points? If none of them is in the triangle by others, how can I connect them in order to form a 4 edges polygon, instead of two head on triangles, when using order 1-2-3-4-1? like this: 1----2 \ \ 4\__\3 not like this: 1-----2 \ / /\ / \ 3-----4 Thanks, Qian