[GRASS-stats] new module for multiple regression with large raster maps

Markus Metz markus.metz.giswork at googlemail.com
Tue Nov 8 04:28:59 EST 2011


Dylan Beaudette wrote:
> On Friday, October 07, 2011, Markus Metz wrote:
>> 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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>>
>
> Very cool. Can this module fit models from point data, and produce predictions
> in the form of a raster?

Yes, as of r49130. Residuals are also available as output raster.

Markus M


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