Discarding function outputs

I wish I'd known MATLAB had... [~,Y]=F()

• If you don't want the first return value from a function, but you want the second one, you can discard the first one with ~.
• The main advantage is it doesn't clutter your workspace with dummy variables like temp, z, or whatever you use for unwanted variables.
• Common examples might include:
  [~,E]=eig(X)      if you want the eigenvectors but not the eigenvalues
  [~,~,kcode] = KbCheck
           in psychtoolbox to get just the key codes of currently depressed keys