Ability to compare separate runs

[GoogleCodeExporter]

As requested by Bharat Mediratta:

"Hey Joakim.  Thanks again for webgrind, it is very useful.  I'm using it to 
optimize Gallery3 and 
one of my most common operations is to make a change and try to predict then 
demonstrate a 
performance delta.  The way I do it now is that I do a couple of 
?XDEBUG_PROFILE runs before 
and after my change, then open them all up in tabs in Chrome and switch back 
and forth 
between the two to compare numbers.

What would help me there would be a way to figure out the delta between two 
runs so that I 
could get an idea of the impact of a change.  Eg, it would be very nice to know 
that function foo() 
took up 10% of my total request processing time before and 7% afterwards.

As a bonus if I could aggregate a set of runs and label them, then compare 
between labels I 
could use the aggregation to reduce the noise between multiple runs.  Simple 
aggregation that 
just took the average would be a fine start although in a perfect world I could 
do 10 runs and it 
would drop the outliers.

Not a trivial request, I'm sure.  Thanks for your consideration!"

Original issue reported on code.google.com by gugakf...@gmail.com on 12 Mar 2009 at 1:26

[GoogleCodeExporter]

Agreed - This is the number 1 feature I could use as well. Just being able to 
compare the current run with the last would be extremely helpful (something 
like a little +10% next to the current percentage, or -42ms next to the current 
time).

Original comment by JohnBO...@gmail.com on 5 Aug 2010 at 9:12