## inside triangle

version 1.0.0.0 (1.51 KB) by
inside_triangle is used to check if a point P is inside the triangle P1P2P3 or not.

Updated 15 Jan 2009

%inside_triangle is used to check if a point P is inside
%the triangle P1P2P3 or not.
%
%Inputs: P, P1, P2 and P3 are vectors of length 2 or three of the
% form [x y z] or [x y]
%
%Output: True
%True=1 => P is on or inside P1P2P3
%True=0 => P is outside P1P2P3
%
%Example:
%True=inside_triangle([0.5 0.5],[0 0],[0 2],[2 0]);
%
%The following algorithm is implemented
% If P is ON or INSIDE the triangle
%
% Area(PP1P2) + Area(PP2P3) + Area(PP3P1) = Area(P1P2P3)
%
% If P is OUTSIDE then,
%
% Area(PP1P2) + Area(PP2P3) + Area(PP3P1) > Area(P1P2P3)
%
% Area of a triangle can be found using the determinant:
%
% Area = abs(1/2 * |x1 y1 1| )
% |x2 y2 1|
% |x3 y3 1|
%

### Cite As

Nassim Khaled (2021). inside triangle (https://www.mathworks.com/matlabcentral/fileexchange/22690-inside-triangle), MATLAB Central File Exchange. Retrieved .

##### MATLAB Release Compatibility
Created with R14SP1
Compatible with any release
##### Platform Compatibility
Windows macOS Linux

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