Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: PCA scores on different data?


From   "K Jensen" <k.x.jensen@googlemail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: PCA scores on different data?
Date   Sat, 16 Feb 2008 15:37:55 +0000

Thanks Martin. As ever--the perfect solution!
Karin

On 16/02/2008, Maarten buis <maartenbuis@yahoo.co.uk> wrote:
> --- K Jensen <k.x.jensen@googlemail.com> wrote:
> > I would like to calculate the scores derived from a PCA using one
> > Stata data set to the observations in a second data set. How could I
> > go about doing this?
>
> An often very useful feature of -predict- is that it doesn't care
> whether you changed any of the variables or even if you are in the same
> dataset, it just needs the variable names to be the same as in the
> model you estimated. See the example below:
>
> *----------------------- begin example --------------------
> // make two files
> tempfile a b
> sysuse auto, clear
> keep if foreign == 1
> save `a'
> sysuse auto, clear
> keep if foreign == 0
> save `b'
>
> // do pca
> use `a', clear
> pca weight length turn displacement gear_ratio, comp(1)
>
> // calculate scores in file b
> use `b', clear
> predict size, score
> *-------------------- end example -------------------------
> (For more on how to use examples I sent to the Statalist, see
> http://home.fsw.vu.nl/m.buis/stata/exampleFAQ.html )
>
> Hope this helps,
> Maarten
>
> -----------------------------------------
> Maarten L. Buis
> Department of Social Research Methodology
> Vrije Universiteit Amsterdam
> Boelelaan 1081
> 1081 HV Amsterdam
> The Netherlands
>
> visiting address:
> Buitenveldertselaan 3 (Metropolitan), room Z434
>
> +31 20 5986715
>
> http://home.fsw.vu.nl/m.buis/
> -----------------------------------------
>
>
>       __________________________________________________________
> Sent from Yahoo! Mail - a smarter inbox http://uk.mail.yahoo.com
>
> *
> *   For searches and help try:
> *   http://www.stata.com/support/faqs/res/findit.html
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index