[GRASS-stats] Re: [GRASS-user] Testing i.pca ~ prcomp(), m.eigensystem ~ princomp()

[Markus Neteler]

On Tue, Mar 31, 2009 at 5:00 PM, Markus Metz
<markus.metz.giswork at googlemail.com> wrote:
> Nikos Alexandris wrote:
>> Using MODIS (range varries between bands, up to max. ~5500):
>>
>
> Sure? Valid range: -100 - 16000 for MODIS e.g. Surface Reflectance 8-Day L3
> Global 500m.

Remember that you have to rescale these data first:

https://lpdaac.usgs.gov/lpdaac/products/modis_products_table
-> MOD09Q1  	Terra  	Surface Reflectance Bands 1–2  	Tile  	250m  	8 Day
    https://lpdaac.usgs.gov/lpdaac/products/modis_products_table/surface_reflectance/8_day_l3_global_250m/v5/terra
   -> layers

... MULTIPLY BY SCALE FACTOR ...

best,
Markus