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Algorithm for PCA transform in ENVI [message #80072]

Tue, 08 May 2012 09:57

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

Junior Member

Does anybody know what the algorithm for PCA transform in ENVI is?
I've compared the eigenvectors and the spatial patterns of ENVI's PCA
transform with IDL's eigenql, svdc and la_svd procedures. The first PC
components are the same but from the second component on I have
negative values where ENVI give positive values and vice versa.
Accordingly, the first element in the diagonal of the eigenvector
matrices has the same sign but the rest of the signs are just the
oppostie comparing results from ENVI and IDL.
Any clues?
Thanks in advance,
Eva

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		Algorithm for PCA transform in ENVI By: eva.ivits-wasser on Tue, 08 May 2012 09:57
		Re: Algorithm for PCA transform in ENVI By: ivitseva on Fri, 11 May 2012 07:02

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