comparing maps

[Darrell McCauley]

> 	What methods are there for comparing two maps for
> simularity? I am interested in the correlation and not
> interested what the relationship is (slope,intercept). 	I've
> used r.covar but was wondering what other methods others have
> used to compare two maps.

Of course this depends on what type of maps you are comparing,
but i.texture may give useful information.

from the manual page:

man> i.texture - calculate textural features on a raster file
man> 
man> Features include:
man> (1) Angular Second Moment,		(2) Contrast,
man> (3) Correlation,			(4) Variance,
man> (5) Inverse Difference Moment,	(6) Sum Average,
man> (7) Sum Variance,			(8) Sum Entropy,
man> (9) Entropy,			(10) Difference Variance,
man> (11) Difference Entropy,		
man> (12, 13) Information Measures of Correlation, and
man> (14) Maximal Correlation Coefficient.

i.texture should be in the incoming directory on moon and is also available 
at pasture.ecn.purdue.edu:/pub/mccauley/grass/i.texture.shar.Z

--Darrell