[R] nipals in the chemometrics package in R

Pedro Mardones mardones.p at gmail.com
Mon Dec 5 16:06:10 CET 2011


Perhaps you can try the examples given in
http://www.jstatsoft.org/v18/i02 for getting a better idea about how
the NIPALS algorithm works. BTW, yes,it looks like a homework question
specially when your user name is "zz dd <void1999 at gmail.com>" so you
can't be recognized.



On Mon, Dec 5, 2011 at 9:27 AM, zz dd <void1999 at gmail.com> wrote:
> Thank you for your brevity you don't have to say more things to show who
> you are.
> Else if you don't understand what we are talking about, you shouldn't  be
> rude and insulting.
> May be you are quite young please take time to read Nonaka and Takeuchi and
> moreover Takanashi to uderstand the way to go from information to knowledge
> to wisdom that's quite useful for IS / IT and should bring you a bit of
> etiquette.
> *I have a dream* *that one day this nation will rise up and live out the
> true meaning of its creed : “We hold these truths to be self-evident : that
> all men are created equal.”*
>
> Have a nice day.
>
> 2011/12/5 Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
>
>> This is not a homework help list.
>> ---------------------------------------------------------------------------
>> Jeff Newmiller                        The     .....       .....  Go Live...
>> DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live
>> Go...
>>                                      Live:   OO#.. Dead: OO#..  Playing
>> Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
>> /Software/Embedded Controllers)               .OO#.       .OO#.  rocks...1k
>> ---------------------------------------------------------------------------
>> Sent from my phone. Please excuse my brevity.
>>
>> zz dd <void1999 at gmail.com> wrote:
>>
>> >Hello
>> >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
>> >Xres
>> >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
>> >component.
>> >
>> >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....
>> >>
>> >
>> >       [[alternative HTML version deleted]]
>> >
>> >______________________________________________
>> >R-help at r-project.org mailing list
>> >https://stat.ethz.ch/mailman/listinfo/r-help
>> >PLEASE do read the posting guide
>> >http://www.R-project.org/posting-guide.html
>> >and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
>        [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



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