[R] nipals in the chemometrics package in R

Jeff Newmiller jdnewmil at dcn.davis.ca.us
Mon Dec 5 12:48:35 CET 2011

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zz dd <void1999 at gmail.com> wrote:

>The solution maybe there but i need to compute it into R if someone can
>help me :
>(Previously store score vector t in score matrix T; store loading
>vector p
>in loading matrix P) that's done by nipals in chemometrics
>After use of nipals function you have T and P matrix
>First : "Calculate the residual matrix of X. Stop if the elements of
>are very small
>because no further PCA components are reasonable" :
>Xres= X-u.b(T)
>u : improved score vector
>b: loading vector
>X : a mean-centered matrix
>Second : Replace X with Xres and continue with step 2 (with nipals
>chemometrics...) for calculation of the next PCA
>If someone can help me ?
>Thank's a lot
>2011/12/1 zz dd <void1999 at gmail.com>
>> Hello
>> i need some precision about nipals in the chemometrics package in R .
>> When i use nipals in chemometrics i obtain T and P matrix.
>> I really don't understand what to do with these two matrix to obtain
>> the scores for every the component (like in spss fo example)
>>             Comp1    Comp2   Comp3
>> quest1 0,8434      0,54333   0,3466
>> quest2 0,665       0,7655      0,433
>> Thank you very much for your help
>> (I know that X=TP+E)... But don't understand else....
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