Line 129 in saveas function is slow!

I'm plotting some figures in a script where I create a single figure and then clear the figure and replot to the current axes. I save the figures using saveas after each figure is plotted. Saveas is called 16 times (8 times it saves as a .fig and 8 it saves as a .ai). My function is taking nearly 5 minutes to run with 98.9% of that being saveas line 129 which is this:

if ~isempty(format) && any( exist( ['saveas' format]) == [2 3 5 6] ) %#ok

It doesn't make sense to me that this line should take so long. I'm using Matlab 2007b. Here is the profiler output.

Lines where the most time was spent Line NumberCodeCallsTotal Time% TimeTime Plot 129if ~isempty(format) &&...16 280.099 s98.9% 130feval( ['saveas' format], h, n...81.907 s 0.7% 159print( h, name, ['-d' dev{i}] ...81.121 s 0.4% 136[ops,dev,ext] = printtables; %...80.017 s0.0% 160return80 s0%All other lines 0 s0% Totals 283.145 s100%

Thanks in advance.

Justin

Answer 1

[Oliver Woodford]

If the question were instead "How can I make saveas faster?", I'd say -

Change line 129 to:

if ~isempty(format) && ~isempty(strmatch(format, char('fig', 'm', 'mfig', 'mmat'), 'exact'))

[Fangjun Jiang]

Yes, good idea! The rest of saveas.m did use strmatch( , ,'exact') to compare other format such as .bmp or .eps. This could be a nice enhancement of the saveas() function.

Answer 2

[Fangjun Jiang]

It is true for me too. That line consumes more than half of the time if I save the plot to a .fig file and repeat it a dozen times.

You could put it in a good way that the other part of the code is fast.

To understand it further, the time consuming part is the exist() function, it tries to see if a file named 'saveasfig' exists in the MATLAB path. It does and it's a private function. It could also search for saveasfig.mex, saveasfig.p. That is what [2 3 5 6] for.

It sounds unreasonable that it spent 280 seconds on that line of code, unless your computer is really old and slow. I suggest you check your MATLAB path and remove unnecessary folders in it. Run rehash might also help.

>> which saveasfig -all

.\MATLAB\R2007b\toolbox\matlab\general\private\saveasfig.m  % Private to general

[Justin]

My computer isn't old, it's practically new. It's a 64 bit machine running 32 bit Matlab with Windows 7.

I'll try rehash. It could also be that I have a lot of folders in my MATLAB path. I'll also try limiting those. Thanks!