[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
<BLOCKQUOTE style='PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #A0C6E5 
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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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list<br>>Bioconductor at stat.math.ethz.ch<br>>https://stat.ethz.ch/mailman/listinfo/bioconductor<br></font></BLOCKQUOTE>
    
    
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