I did Exercise 3.1 by commenting the code. However while doing Exercise 3.2 onwards part (a) I am getting some errors. I had pasted my code below the pictures.

load ('lighthouse.mat')
w = 15; 
x = 1:160; 
y = 1:80; 
z = round (127* exp(-1/w.^2*((y.'-40).^2+(x -80).^2)));
colormap ( gray );
[xs ,ys ,zs] = image_sample(z ,2);
za = image_system2 (zs , -10 ,35);
zb = image_system3 (za , -30 ,35);
figure (1); 
subplot (2 ,2 ,1); 
imagesc (x, y, z); 
axis image ; 
title ('Original')
subplot (2 ,2 ,2);
imagesc (xs , ys , zs); 
axis image ; 
title ('After Sampling')

[Walter Roberson]

What is the error message?

[SZ N]

I keep getting this error

Answer 1

[Steven Lord]

Your assignment instructs you to write a MATLAB function image_sample but you have written a MATLAB script image_sample. See this documentation page for some information about the differences between functions and scripts.

[SZ N]

Im still not getting the desired output :{..The plot just grey. Could you please help me out?

[Walter Roberson]

The code about loading an initializing variables needs to go in LAB3.m or similar name.

The first line of image_sample.m needs to start with the word "function".

The function in image_sample.m needs to be called from outside of image_sample.m and that cannot happen if image_sample.m is a script.