[BioC] question about Limma
? ?
chenhuan7809 at msn.com
Fri Jul 22 12:34:48 CEST 2005
Dear Sir
I am a novice to limma. I meet some questions and can't solve these by
myself. So please give me a hand.
firstly, I wonder could I use two wt.fun to filter bad spot, for
example:
myfun1 <- function(x, threshold=50) {
+ okred <- abs(x[,"F635 Median"]-x[,"F635 Mean"]) < threshold
+ okgreen <- abs(x[,"F532 Median"]-x[,"F532 Mean"]) < threshold
+ as.numeric(okgreen & okred)
+}
myfun2 <- function(x) as.numeric(x$Flags > -99)
I think "myfun1" can help me to filter outliers and "myfun2" can help to
filter bad spots according to Genepix output file(.gpr file). Could I
combind two filter ways to filter spots, and how?
Secondly, question about "duplicateCorrelation", there is a example in
your limma usersguide to solve all genes (ESTs and controls) are printed
more than once on the array, in my microarray, every gene have
duplication,the command is "cor <-
duplicateCorrelation(MA,design,ndups=2)", but when I do some technical
replication, how can I use this function? (when it comes to technical
replication, ndups will equal to 1,how to compute correlation within array
duplication? And I isolate RNA from bacterial not animal bodys, how to say
biological replication?).
Finally, how to extract information from the eBayes function, I mean
could I get $coef,$lods,$genes,etc simultaneously, as .gal file input
order.
Thanks your help.
Best regards
Chen
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