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Re: normalisation of PCA bands [message #77968 is a reply to message #77966]

Fri, 14 October 2011 00:59

eva.ivits-wasser
Messages: 8
Registered: October 2011

Junior Member

On Oct 13, 6:14 pm, alx <lecacheux.al...@wanadoo.fr> wrote:
> On 13 oct, 09:58, eva.ivits-was...@ext.jrc.ec.europa.eu wrote:
>
>> Good morning!
>
>> How can I normalisePCAbands so that they have values between -1 and
>> 1? Is it a simple min-max scaling or is there a more sophisticated,
>> correct way to do it?
>
>> Thanks in advance,
>> Eva
>
> You may use the STANDARDIZE function which normalizes the variance and
> subtracts the average of each band.
> alx.

Hi Alex,

Thanks but I'm afraid it isn't that I'm looking for.

In meteorological publications I've read the following statement:
"the spatial patterns (eigenvectors) properly normalized (divided by
their Euclidean norm and multiplied by the square root of the
corresponding eigenvalues) are called loadings; they represent the
correlation between the original data (the time series) and the
corresponding principal component time series."

Doing this the PCA bands will have values between -1 and 1.
Unfortunately I do not really understand the meaning of the above
sentence...

Any idea?

Thanks,

Eva

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[Message index]

		Re: normalisation of PCA bands By: lecacheux.alain on Fri, 14 October 2011 04:51
		Re: normalisation of PCA bands By: eva.ivits-wasser on Fri, 14 October 2011 00:59
		Re: normalisation of PCA bands By: lecacheux.alain on Thu, 13 October 2011 09:14

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