Can anyone please help me to understand the problem here? I keep getting the error "Index exceeds matrix dimensions".

for i = 1:length(circles)
  if  (circles(i,1) ~= 0 & peaks(i,2) ~= 0)
    xp = peaks(3,i).*cos(ang);
    yp = peaks(3,i).*sin(ang);
  end
end

Answer 1

[Walter Roberson]

Replace length(circles) by size(circles,1)

[Fadil]

changing it to size(circles,2) works. Thank you.

[Walter Roberson]

You index circles(i,1) so i should be at most size(circles,1)

Notice though that in your "if" you index peaks(i,2) but after that you index peaks(3,i) which switches the position of the "i" .

Answer 2

[Matt J]

You've done something similar to the following,

 >> x=1:5; a=x(6)

Answer 3

[Andrei Bobrov]

if size(circles,1) == size(peaks,1)
  dc = cellfun(@(f)f(ang).*peaks(3,circles(:,1) & peaks(:,2)),{@cos,@sin},'un',0);
  [xp,yp] = dc{:};
end