Length of cave and length of surveys

[John Pybus]

Olly Betts wrote:

> 
>>It might also be useful if it reported the amount of surface survey as well.
> 
> I think the way to go is to put the functionality in Aven.  Then you can
> specify a subsurvey you'd like statistics for (e.g. a single cave if the
> dataset is all your caves), and say exactly which classes of legs you'd
> like included in the length.

Personally, I'd prefer that functionality which doesn't require visual 
interaction not be _only_ in aven.  This sort of statistic gathering is 
what I'd use in Makefiles/scripts which control processing of data.  I 
don't see that it would be hard to have the same code link to a visual 
interface in aven as well as command line tools.

John