Summarizing Single-channel Agilent data
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@gordon-smyth
Last seen 11 hours ago
WEHI, Melbourne, Australia
Dear David, What you do mean by "summarizing". Are you perhaps looking for avereps()? BTW, the read can be done slightly more succintly by RG <- read.maimages(targets,source="agilent.median",green.only=TRUE) Best wishes Gordon > Date: Fri, 2 Mar 2012 15:51:00 +0100 > From: David Westergaard <david at="" harsk.dk=""> > To: bioconductor at r-project.org > Subject: [BioC] Summarizing Single-channel Agilent data > > Hello, > > I am working on normalizing raw data from > http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-33005 using the > Limma package. > > Following "standard" procedure, I do background correction, and then normalize: > > # Read target from file > targets <- readTargets("targets") > RG <- read.maimages(targets,source="agilent", columns =list(G = > "gMedianSignal", Gb = "gBGMedianSignal"),green.only=TRUE) > > > # Do backgroundcorrection/normalization > RG <- backgroundCorrect(RG, method="normexp") > RG <- normalizeBetweenArrays(RG, method="quantile") > > Now, what I'm lacking is a summarization method. Googling abit, > "Agi4x44PreProcess" can do the summarization, but it doesn't accept > single-channel data. Furthermore, it expects an RGList as input to > summarize.probe (NormalizeBetweenArrays produces an EList) > > So how would I go about summarizing these data? It would be nice if > there was an existing package doing this. > > > Best Regards, > David Westergaard > Undergraduate student > Technical University of Denmark > ______________________________________________________________________ The information in this email is confidential and intend...{{dropped:4}}
GO limma GO limma • 971 views
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@gordon-smyth
Last seen 11 hours ago
WEHI, Melbourne, Australia
Dear David, Here's a complete limma analysis of the Agilent data on ArrayExpress. It would appear that only the 10 ml/kg treatment is different from the saline control. There are 12000 differential expressed genes for the 10 ml/kg treatment. Best wishes Gordon > SDRF <- read.delim("E-GEOD-33005.sdrf.txt",check.names=FALSE,strings AsFactors=FALSE) > x <- read.maimages(SDRF[,"Array Data File"],source="agilent.median",green.only=TRUE) Read GSM819076_US10283824_252828210181_S01_GE1_107_Sep09_1_4.txt Read GSM819075_US10283824_252828210181_S01_GE1_107_Sep09_1_3.txt Read GSM819074_US10283824_252828210181_S01_GE1_107_Sep09_1_2.txt Read GSM819073_US10283824_252828210180_S01_GE1_107_Sep09_1_4.txt Read GSM819072_US10283824_252828210180_S01_GE1_107_Sep09_1_3.txt Read GSM819071_US10283824_252828210180_S01_GE1_107_Sep09_1_2.txt Read GSM819070_US10283824_252828210180_S01_GE1_107_Sep09_1_1.txt Read GSM819069_US10283824_252828210179_S01_GE1_107_Sep09_1_4.txt Read GSM819068_US10283824_252828210179_S01_GE1_107_Sep09_1_3.txt Read GSM819067_US10283824_252828210179_S01_GE1_107_Sep09_1_2.txt Read GSM819066_US10283824_252828210179_S01_GE1_107_Sep09_1_1.txt Read GSM819065_US10283824_252828210178_S01_GE1_107_Sep09_1_4.txt Read GSM819064_US10283824_252828210178_S01_GE1_107_Sep09_1_3.txt Read GSM819063_US10283824_252828210178_S01_GE1_107_Sep09_1_2.txt Read GSM819062_US10283824_252828210178_S01_GE1_107_Sep09_1_1.txt Read GSM819061_US10283824_252828210177_S01_GE1_107_Sep09_1_4.txt Read GSM819060_US10283824_252828210177_S01_GE1_107_Sep09_1_3.txt Read GSM819059_US10283824_252828210177_S01_GE1_107_Sep09_1_2.txt Read GSM819058_US10283824_252828210177_S01_GE1_107_Sep09_1_1.txt > y <- backgroundCorrect(x,method="normexp") > y <- normalizeBetweenArrays(y,method="quantile") > neg99 <- apply(y$E[y$genes$ControlType==-1,],2,function(x) quantile(x,p=0.99)) > cutoff <- matrix(neg99,nrow(y),ncol(y),byrow=TRUE) > isexpr <- rowSums(y$E > cutoff) >= 4 > table(isexpr) isexpr FALSE TRUE 4321 39933 > y0 <- y[y$genes$ControlType==0 & isexpr,] > Treatment <- SDRF[,"Characteristics[treatment]"] > levels <- c("10 ml/kg saline","2 ml/kg corn oil","5 ml/kg corn oil","10 ml/kg corn oil") > Treatment <- factor(Treatment,levels=levels) > design <- model.matrix(~Treatment) > yave <- avereps(y0,ID=y0$genes[,"SystematicName"]) > fit <- lmFit(yave,design) > fit <- eBayes(fit,trend=TRUE) > summary(decideTests(fit[,-1])) Treatment2 ml/kg corn oil Treatment5 ml/kg corn oil Treatment10 ml/kg corn oil -1 0 0 384 0 24433 24433 23207 1 0 0 842 On Sun, 4 Mar 2012, Gordon K Smyth wrote: > Dear David, > > What you do mean by "summarizing". Are you perhaps looking for avereps()? > > BTW, the read can be done slightly more succintly by > > RG <- read.maimages(targets,source="agilent.median",green.only=TRUE) > > Best wishes > Gordon > >> Date: Fri, 2 Mar 2012 15:51:00 +0100 >> From: David Westergaard <david at="" harsk.dk=""> >> To: bioconductor at r-project.org >> Subject: [BioC] Summarizing Single-channel Agilent data >> >> Hello, >> >> I am working on normalizing raw data from >> http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-33005 using the >> Limma package. >> >> Following "standard" procedure, I do background correction, and then >> normalize: >> >> # Read target from file >> targets <- readTargets("targets") >> RG <- read.maimages(targets,source="agilent", columns =list(G = >> "gMedianSignal", Gb = "gBGMedianSignal"),green.only=TRUE) >> >> >> # Do backgroundcorrection/normalization >> RG <- backgroundCorrect(RG, method="normexp") >> RG <- normalizeBetweenArrays(RG, method="quantile") >> >> Now, what I'm lacking is a summarization method. Googling abit, >> "Agi4x44PreProcess" can do the summarization, but it doesn't accept >> single-channel data. Furthermore, it expects an RGList as input to >> summarize.probe (NormalizeBetweenArrays produces an EList) >> >> So how would I go about summarizing these data? It would be nice if >> there was an existing package doing this. >> >> >> Best Regards, >> David Westergaard >> Undergraduate student >> Technical University of Denmark >> > ______________________________________________________________________ The information in this email is confidential and intend...{{dropped:4}}
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