[GRASS-user] Change detection in a Vector (polyline) dataset

[Andrew Schroeder]

Hi Everyone,

Can you tell me if GRASS is able to detect change between two input 
polyline shapefiles?  I have a 5m contour set for two different years at 
a particular mine, and I'm looking for a way to automate detection of 
the yearly pit advances.

Basically, I'm looking for something to subtract file A from file B 
(b-a=change) and output a file showing just the lines that changed 
between the two files.

Thanks for any direction you can offer.

Andrew Schroeder