how to make a matlab code that finds the area of a polygon using 2 different matrices, x and y coordinates?

i need to write a code to find the area of a polygon with a matrix equation using x and y coordinates that also includes a special matrix

Answer 1

[KSSV]

If you want to use a straight away function doc polyarea.

If you want to write a function, then it depends is your polygon a regular polygon. If regular polygon, then you can use the formulas to calculate the areas. Or, you can split the polygon into triangles, calculate the area of each triangle and sum them.

http://www.wikihow.com/Find-the-Area-of-Regular-Polygons

[Alex Hogan]

yeah i need to split it into triangles

[KSSV]

Try this:

clc; clear all ;
t = (1/16:1/8:1)'*2*pi;
x = cos(t);
y = sin(t);
polygonVertices =[x y] ;

polygonEdges = [1 2;...  %# Polygon edges (indices of connected vertices)
                2 3;...
                3 4;...
                4 5;...
                5 6;...
                6 7;...
                8 1];

dt = DelaunayTri(polygonVertices,polygonEdges);  %# Create a constrained triangulation
isInside = inOutStatus(dt);  %# Find the indices of inside triangles
faces = dt(isInside,:); 

plot(polygonVertices(:,1),polygonVertices(:,2))
hold on
triplot(dt)