Intersection of two lines in 2D

Takes four points, gives intersection of their connecting lines

Description

Extremely basic tool, saves the drudgery of doing it yourself.
Takes a,b,u,v (points in the form [ x y]) and computes where the lines a->b and u->v will intersect.
Returns point.
No error checking.

• MATLAB release: MATLAB 7.4 (R2007a)
• Other Files: intersection.m, ; license.txt

[Duane Hanselman]

function name duplicates a standard MATLAB function name that finds the intersection of two sets.
poor help, no error checking, etc.

content of the file is:
%computes the intersetion of a_b and u_v
% a b u and v have to be 2d point vectors eg. a = [3 4];
x1=a(1);
x2=b(1);
x3=u(1);
x4=v(1);
y1=a(2);
y2=b(2);
y3=u(2);
y4=v(2);

ua = ((x4-x3)*(y1-y3)-(y4-y3)*(x1-x3))/((y4-y3)*(x2-x1)-(x4-x3)*(y2-y1));
x = x1 + ua*(x2 - x1);
y = y1 + ua (y2 - y1);
p = [x,y];