I use S-PLUS 7.0 on Windows (Probably the same would
happen for version 6).
I tried to perform a PCA analysis on a test dataset
(just random normal numbers) of 100 rows and 1000 columns. I wanted to simulate
what would happen if one uses the menu sytem to analyse a dataset of this size
by clicking the variables they want in their analysis.
I got a result as expected, but when I looked closer
I saw only the first 260 elements of the formula where used to calculate the
PCA. I changed the names of the dataset into longer names to test if the number
of elements would reduce, but it stayed 260 elements (to be sure it was not the
formula field itself that could not handle such a long formula).
This was a problem because I made a PCO menu-system
in about the same format as the PCA-menu sytem where a dataset that includes
both some descriptive variables and the binary levels of the occurrence of genes
are allowed as input (that is the way the scientists get their data and I did
not want to make it too difficult for them to be forced to change their
dataset)
I tried to find out if this behaviour was similar in the
command language:
fmla <-
paste('~',paste('X.',1:334,sep="",collapse=" + "))
setf <- parse(text=setformula)
This gives a stack overflow when one looks into the
setf variable
When only 333 elements used it was no problem.
Is there a way to make sure all the 1000 elements are
used for an analysis, without taking into account the alternative that a PCA
analysis can also be performed by the command language princomp(data) or by
using the <ALL> or ~. in the menusytem as formula? It is also strange
that the menu system only accepts 260 instead of 333.
Kind regards,
Pieter