MATLAB: What does this error with tic\toc means

Question

i have this problem – matlab tells me I have an error while running-

 Error using toc
 You must call TIC without an output argument before calling TOC without an
 input argument.
 Error in hand_rotation2/youPress (line 126)
             c = toc;
 Error while evaluating figure KeyPressFcn

what does it mean, and how can I fix it?

Answer 1

It means to use toc, you have to call tic first somewhere

 tic;
 for ii = 1:10
  x(ii) = ii+1;
 end
 y = toc;

If you use toc by itself, it must have been preceded by a tic command sometime during the current session, then it gives the time since the most recent tic command. In this latter case, that is probably not what you want.