Re: C++ version of regexprep.cc

[Paul Kienzle]

On May 2, 2006, at 10:57 AM, David Bateman wrote:

> I just noted, you didn't state whether this improved the speed of your 
> xml code sufficiently or not... Or whether there is a another speed 
> problem elsewhere.

mat2cell is slower than I expect.  It needs an OCTAVE_QUIT in its loop.

The particular file that I'm trying to load is 500 kb, with about 6000 
separate values, so 12000 separate open/close tags, and 24000 elements 
in the partition.  I was expecting this to take a couple of seconds but 
instead it takes 2 1/2 minutes.

Running some tests, the behaviour of mat2cell is quadratic over 
[1000,10000].  Looking at the code I can't tell why.

You can try running 'speed' on it (I'm not tunneling X so I can't right 
now):

        speed("v=mat2cell(s,1,p);","s=repmat('a',1,n);p=ones(1,n);",10000);


mat2cell is still fast compared to the for loop in xml2mat which builds 
the cell structure from the xml.

At this point I'm going to declare defeat and say that xml2mat won't 
run on octave with large files in reasonable time.

- Paul