Please Help, I am getting this error "Index in position 1 is invalid. Array indices must be positive integers or logical values."

I havean image (P) and generated 4000 random samples and stored in variable row and col. Then, from my image P, i want

to have array of P(row,col) position and the next horizontal Neighbour P(row,col+1).

P= imread('cameraman.tif');

for i = 1 : 4000

row = round(rand() * 255);

col = round(rand() * 255);

x(i) = P(row,col) ; % the first pix value

y(i) = P(row,(mod((col+1),256))); % the Horizontal neighbour

end

Answer 1

[Dave B]

If the result of calling rand is small (less than 1/255) then round(rand*255) will be 0, and 0 isn't a valid index.

Consider using randi(255) instead of rand*255? Or use something like ceil(rand*255) (as you're wrapping around for edge values with mod anyway)

[Abubakar Abba]

Thank you