[BioC] how to run SAM analysis
M a r c e l
benco81 at hotmail.com
Fri Sep 2 19:24:24 CEST 2005
hi!
if you want to run SAM anaylsis anyway, try the following (not sure if it
works that way, but worth a try)
for example (RMA or gcRMA as you want, for gcRMA load the library gcRMA)
data.norm <- rma(data, normalize = TRUE, background = TRUE)
now construct the vector cl as needed by the SAM function:
cl <- c(0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)
or
cl <- rep(0:1, c(3,14))
with 0 being the normal tissues and 1 the diseased ones. (use pData(data) to
see the correct order of your data)
and then:
data.sam <- sam(data.norm, cl)
don´t forget to filter the genes with the genefilter function (
genefilter(data,flist) ) in the genefilter library!
please everyone send me positive or negative answers, would appreciate if my
instructions were correct or not. thanks!
cheers,
gregor
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From: <i>Adaikalavan Ramasamy
<ramasamy at cancer.org.uk></i><br>Reply-To:
<i>ramasamy at cancer.org.uk</i><br>To: <i>weinong han
<hanweinong at yahoo.com></i><br>CC:
<i>bioconductor at stat.math.ethz.ch</i><br>Subject: <i>Re: [BioC] how to run
SAM analysis</i><br>Date: <i>Thu, 01 Sep 2005 22:48:51
+0100</i><br>>Your design is seriously unbalanced and under-powered. I
would suggest<br>>you increase the sample size in the normal group. This
holds no matter<br>>what test statistics you plan on
using.<br>><br>>LIMMA would probably be better for your purposes. I
_think_ it has been<br>>shown empirically to hold for small sample
sizes.<br>><br>>Regards, Adai<br>><br>><br>><br>>On Wed,
2005-08-31 at 19:22 -0700, weinong han wrote:<br>> > Hi, List,<br>>
><br>> > I have 17 affymetrix .cel files and ran RMA analysis on
them. Now I want to run SAM analysis(unpaired, 3 normal tissues and 14
diseased tissues) on the RMA data with R2.1.1.<br>> > I have
installed the samr package.<br>> ><br>> > Questions: How to run
the SAM analysis after the RMA analysis? The better, the more detailed
explanations.<br>> ><br>> > Any advice and suggestions will be
much appreciated.<br>> ><br>> ><br>> ><br>>
><br>> > Best Regards<br>> ><br>> > Han Weinong<br>>
> hanweinong at yahoo.com<br>> ><br>> >
__________________________________________________<br>> ><br>>
><br>> ><br>> > [[alternative HTML version deleted]]<br>>
><br>> > _______________________________________________<br>>
> Bioconductor mailing list<br>> >
Bioconductor at stat.math.ethz.ch<br>> >
https://stat.ethz.ch/mailman/listinfo/bioconductor<br>>
><br>><br>>_______________________________________________<br>>Bioconductor
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