Icebergs - XML file metrics

[Robin LaFontaine <robin@monsell.co.uk>]

Can anyone help with this: Is there a way of 'profiling' an XML file 
to indicate its characteristics?

We test our XML comparators on large files, but a 5Mb XML file could 
have twenty XML tags or 20,000 and it could be deeply nested or flat. 
So, are there any metrics to help in this characterization?

Seems sensible to use ratios as far as possible, so that they are 
comparable for different file sizes, perhaps:

1. File size (not a ratio)

2. No. of elements / file size in kb = no. of elements/kb (or Mb perhaps?)

3. No. of attributes / no. of elements = no. of attributes/element

4. No. of text nodes / no. of elements = no. of text nodes/element

5. No. of text nodes / no. of unique text nodes = text re-use index

6. No. of attribute values / no. of unique attr. values = attribute 
value re-use index

7. (sum for each element of no. of ancestors for the element) / no. 
of elements = Average depth (iceberg factor).

Last one indicates nesting depth, e.g.
<a> <b/><b/><b/><b/></a> = (0+1+1+1+1)/5 = 0.8

<a> <b><b><b><b></b></b>/<b></b> </a> = (0+1+2+3+4)/5 = 10/5 = 2

<a> <b><b><b><b> <b><b><b><b> </b></b>/<b></b> </b></b>/<b></b> </a> 
= (0+1+2+3+4+5+6+7+8)/5 = 36/9 = 4

Perhaps someone has already developed a different set of metrics.

Robin
-- -----------------------------------------------------------------
Robin La Fontaine, Monsell EDM Ltd
(XML file comparison, Engineering data exchange and management using 
XML, R&D Project Management)
Tel: +44 1684 592 144 Fax: +44 1684 594 504
Email: robin@monsell.co.uk      http://www.deltaxml.com