[Portugal] [Fwd: [GRASS-user] new module for multiple regression with large raster maps]

[Giovanni Manghi]

-------- Forwarded Message --------
> From: Markus Metz <markus.metz.giswork at googlemail.com>
> To: grass-stats at lists.osgeo.org, grass-user
> <grass-user at lists.osgeo.org>
> Subject: [GRASS-user] new module for multiple regression with large
> raster maps
> Date: Fri, 7 Oct 2011 11:34:20 +0200
> 
> There is a new module r.regression.multi as grass7 add-on to calculate
> multiple regressions with raster maps. The motivation for this module
> is to calculate regression coefficients and statistics for very large
> datasets, too large for e.g. R. The module uses less than 3 MB memory
> for 400 million cells with one response variable and 8 predictors.
> Including residuals, this makes a total of 4 billion numbers.
> Calculation takes about 4 minutes for this dataset on my laptop. In
> addition to the slope estimates, statistics provided are R squared,
> adjusted R squared, F, AIC, corrected AIC, BIC for the full model, and
> F, AIC, corrected AIC, BIC for each predictor. Results are identical
> to those produced by R (with smaller test datasets).
> 
> Markus M
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