[GRASS-dev] PCA (i.pca) in G7: filtering and rescaling

[Nikos Alexandris]

Nikos Alexandris wrote:
> > > > 1) I can't see any differences in the derived Principal Components
..
> > okay, to clarify: I mean the resulting images which, initially are
> > Principal Components (synthetic images) and, after applying filtering &
> > backward PCA, the resulting images approach the original data -- still
> > they are modified.

> Example (using i.pca in G7, though r.info below executed from G64):

>..
>PC1      2.78 ( 0.4947, 0.5922, 0.5743, 0.2735) [69.53%]
>..

Ignore please. I picked the wrong example. It works with percentage = 99 for 
example. Because 70 + 20 = 90 was still inside the 1st component (=96.52).

Sorry for the noise. Then I need to see why the rescaling is not getting at 
[0,255].

Nikos