XML tools for Octave: XML4MAT

[Alois Schloegl]

First the good news:

There is now a possiblity to read a general XML file. Thanks to Paul for 
patching XML4MAT and David for MAT2CELL.CC and REGEXPREP.CC
If you wants to give it a try: you need
- need the latest octave (with mat2cell and regexprep)
- the patched version XML4MAT 
I make this is temporarily available at 
http://hci.tugraz.at/schloegl/biosig/xml/XML4MATv21.zip

An XML-file can be loaded with the command XML2CELL. Paul tested it on 
Octave, I did the test on Matlab.

The good think is, it converts the XML file into one big variable; so no 
complex API's are needed.


The bad news are:
(i) there is a  'recursion level exceeded' error in Octave, when a large 
XML file is used. This is a roadblock. .
( We were using this file 
http://hci.tugraz.at/schloegl/biosig/xml/Exa01.xml )

(ii) a comparison of XML4MAT and XMLTREE takes 80 and 6 seconds, 
respectively.
This shows that there are somewhere some large inefficiencies in the 
algorithm
One reason is perhaps that XML2CELL passes ca. 9 (MBMLING) + 6 (XML2MAT) 
times through the data; XMLTREE builds a tree and converts that tree 
into a structure taking  2(?) passes.

(iii) the representation of the output is "not optimal". There is a 
function "CONSOLIDATE", but it does not work on the test data. This 
would need some serious work.

(v) I tried to contact the author and co-maintainers of XML4MAT, but did 
not receive any response.


What do you think?


Alois