[GRASS-dev] r.resamp.aggregate, trimmed means

Hamish hamish_nospam at yahoo.com
Sun Oct 1 21:55:09 EDT 2006


[r.resamp.stats]

> > > Can we make a decision as to the official name of this module?
> > 
> > how about r.resamp.bin? (as in binning, not binary)
> > 
> > If r.resamp.aggregate is used, I'd vote for using the full word.
> > I don't think "aggregate" abreviates well.
> >
> > by the way, what is this module?
>
> It's a resampling module where the value of the output cell is an
> aggregate (mean, median, mode, min, max etc) of the values from all of
> the input cells whose centres lie within the bounds of the output
> cell.

Hey, that is pretty neat. I can see it being useful for sub-sampling
noisy imagery data with low signal:noise (but > 50%) using a median
filter.

Do we have a way to do a trimmed mean? (eg mean of values between perc10
and perc90; replace 10% with 5% or x%, or 2 Stdevs, etc..) I've always
liked it as a nice compromise between the outlier-discarding ability of
the median and the less arbitrary nature of the mean.
I'd like to have this in r.univar and r.series* too... :)

[*] only useful with many input maps of course


Hamish




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