Data Analysis with R statistical data analysis language provides:
Basic Statistics
Exploratory Data Analysis
Linear Models
Multivariate Analysis
Time Series Analysis
Generalized Linear Models
... and much more!
R-stats is an ideal extension for GRASS. R
is described in greater detail here:
What are R and CRAN. You can
freely download the R
software (MS-Windows/Linux/MacOSX/etc binaries are provided). A general web portal
related to geostatistics is found at AI-GEOSTATS.
Bivand, R. S. and Gebhardt, A. (2000): Implementing functions for
spatial statistical analysis using the R language. Journal
of Geographical Systems 2 (3), pp. 307-317 (online
article, probably restricted access)