mytime(reset)

function mytime(reset)
%
% When called without the reset argument, mytime() displays both time since
% the last invocation and total elapsed time (since the last reset).  If a
% given time value is less than 120 seconds, it is displayed in seconds and
% hundredths of seconds.  If at least 2 minutes but less than 120 minutes,
% it is displayed in minutes and hundredths of minutes.  If greater than or
% equal to 120 minutes, it is displayed in hours and hundredths of hours.
%
% When called with the reset argument (the value of this argument is
% unimportant), the timer is reset to zero.
%
% Dr. Phillip M. Feldman, 15 Feb, 2009

fprintf('%s  ', datestr(now));

persistent t;

if isempty(t) | nargin

   % Start timer:
   tic();
   t= [0 0];
   fprintf('Timer initialized.\n');

else

   t(2)= t(1);
   t(1)= toc();
   dt= t(1) - t(2);

   if dt >= 7200
      str= ['Last step took ' num2str(dt/3600,'%.2f') ' hrs.'];
   elseif dt >= 120
      str= ['Last step took ' num2str(dt/60,'%.2f') ' min.'];
   else
      str= ['Last step took ' num2str(dt,'%.2f') ' sec.'];
   end
   fprintf('%s', str);

   if t(1) >= 7200
      str= ['; total elapsed= ' num2str(t(1)/3600,'%.2f') ' hrs.'];
   elseif t(1) >= 120
      str= ['; total elapsed= ' num2str(t(1)/60,'%.2f') ' min.'];
   else
      str= ['; total elapsed= ' num2str(t(1),'%.2f') ' sec.'];
   end
   fprintf('%s\n\n', str);

end