You asked for SPSS or SYSTAT, but I can't resist mentioning how easy this is in 
R.

For most cases something as simple as the code below would work. All you need 
is a data frame (my.data) with your variables as columns.

my.pca <- prcomp(~ var1 + var2 + var3, data=my.data)

summary(my.pca)
my.pca$rotation

screeplot(my.pca, npcs=3, type="lines")

biplot(my.pca)


In the R console...

?read.table -- getting the data into a data.frame

?prcomp
OR
?princomp -- for the PCA (see 'center' and 'scale' options)

?biplot -- for the biplot

?screeplot -- for a scree plot

HTH,
Dave Hewitt

---- Original message ----
>Date: Fri, 2 May 2008 01:56:11 -0700
>From: Dragos Zaharescu <[EMAIL PROTECTED]>  
>Subject: [ECOLOG-L] Biplot on PCA  
>To: [email protected]
>
>Dear ecologers,
>
>I would much appreciate if someone could provide some information on how to 
>run Biplot on PCA (either for SPSS or SYSTAT)?
>
>Many thanks
> 
>George @ Kingston University
>
>
>      
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