%plot a rect function as a perspective plot
clear all; close all;
N=51;	%generate an N by N array of points
x=0:(1/(N-1)):1; y=x;	% x and y values between 0 and +1 spaced by 1/(N-1) (N values)
[X,Y]=meshgrid(x,y);	% generate 2D grids of xy values (51 by 51 arrays) X(i,j) = x(j) and Y(i,j) = y(i)

Z = zeros(N,N);
Z(abs(X-0.5) < 0.15  & abs(Y-0.5) < 0.2) = 1;
mesh(X,Y,Z)	% generate the perspective plot

colormap([0 0 0]);	% use black only
xlabel('x (ph)'), ylabel('y (ph)');
set(gca,'ydir','reverse');
figure,imshow(Z)