title: matlab error minus , matrix dimensions must agree
body: <p>Hi why am i getting this error?</p>
  
  <pre><code>x = linspace(-1,1,20);
  y = linspace(-2,2,40);
  z = (1.+sin(pi.*x)).*((3.+cos(1.065.*y)).^2).*exp(-x.^2 -(y.^2)./4);
  </code></pre>
  
  <p>??? Error using ==> minus
  Matrix dimensions must agree.</p>