[GRASS-user] About Spatial PCA in GRASS

[Veronica Andreo]

Hi Shiva,

El jue., 12 jul. 2018 a las 2:45, Shiva Khanal (<shiva_khanal at hotmail.com>)
escribió:

> Hi,
>
>
>
> I am interested to run the spatial-mode PCA on raster time series. In R it
> is implemented as an ‘EOF’ function in spacetime Package. The function
> transposes the raster stack and applies ‘prcomp’ function.  I would like to
> know if there is any possible way to implement i.pca similar to this
> approach.
>
>
>
> Interestingly, I found a very good tutorial on GRASS raster time series at
> https://grasswiki.osgeo.org/wiki/Temporal_data_processing/GRASS_R_raster_time_series_processing
> This includes the example using spacetime package to read GRASS raster time
> series into R.
>
>
there's also an alternative way to export raster time series from GRASS
that was not there at the moment of creating the wiki: the add-on
t.rast.out.xyz [0] that produces a table with xy coordinates and all dates
in columns. You can then import that into R, transpose and run prcomp, EOF
or others. Do you want it for gap-filling?

If you dare to implement EOF in GRASS, please go ahead!! I will be very
happy to test and provide feedback, I've been wishing for such a thing (and
also DINEOF) for a while :)

Maybe the devs can provide hints and advice on how to address it.

Best,
Vero

[0] https://grass.osgeo.org/grass74/manuals/addons/t.rast.out.xyz.html
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