Dear Gordon,
Thank you so much for your comments. I have updated my code and get
the different results for TMM and Upper quartile normalization
methods.
I have two more question regarding the normalization issue. I have
tried different normalization methods and would like to compare their
performance. My questions are:
1. In the users' guide 2.5.6, it mentions that normalization takes the
form of correction factors that enter into the statistical model. Such
correction factors are usually computed internally by edgeR functions,
but it is also possible for a user to supply them.I would like to
supply the correct factor to edgeR, how could I do this?
2. I also would like to compare the testing results of normalized data
with the results of raw data (without normalizing the data)? Could I
just skip the the normalization step as below?
group<-paste(L,S,R,sep=".")
design<-model.matrix(~L+R+S+L:R+L:S+R:S+L:R:S)
y<-DGEList(counts=counts,group=group)
#y<-calcNormFactors(y,method="upperquartile",p=0.75) ##skip this step
y<-estimateGLMCommonDisp(y,design)
y<-estimateGLMTagwiseDisp(y,design)
fiteUQ_LRS<-glmFit(y,design,offset=offset )
Thanks.
Yanzhu
-- output of sessionInfo():
sessionInfo()
R version 3.0.1 (2013-05-16)
Platform: x86_64-w64-mingw32/x64 (64-bit)
locale:
[1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United
States.1252 LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C LC_TIME=English_United
States.1252
attached base packages:
[1] parallel stats graphics grDevices utils datasets
methods base
other attached packages:
[1] DESeq_1.12.1 lattice_0.20-15 locfit_1.5-9.1
Biobase_2.20.1 BiocGenerics_0.6.0 edgeR_3.2.4 limma_3.16.8
loaded via a namespace (and not attached):
[1] annotate_1.38.0 AnnotationDbi_1.22.6 DBI_0.2-7
genefilter_1.42.0 geneplotter_1.38.0 grid_3.0.1
[7] IRanges_1.18.4 RColorBrewer_1.0-5 RSQLite_0.11.4
splines_3.0.1 stats4_3.0.1 survival_2.37-4
[13] XML_3.98-1.1 xtable_1.7-1
--
Sent via the guest posting facility at bioconductor.org.
> Date: Fri, 7 Feb 2014 07:25:17 -0800 (PST)
> From: "Yanzhu [guest]" <guest at="" bioconductor.org="">
> To: bioconductor at r-project.org, mlinyzh at gmail.com
> Subject: [BioC] EdgeR multi-factor testing questions
>
>
> Dear Gordon,
>
> Thank you so much for your comments. I have updated my code and get
the
> different results for TMM and Upper quartile normalization methods.
>
> I have two more question regarding the normalization issue. I have
tried
> different normalization methods and would like to compare their
> performance. My questions are:
>
> 1. In the users' guide 2.5.6, it mentions that normalization takes
the
> form of correction factors that enter into the statistical model.
Such
> correction factors are usually computed internally by edgeR
functions,
> but it is also possible for a user to supply them.I would like to
supply
> the correct factor to edgeR, how could I do this?
Just enter in your own values:
y$samples$norm.factors <- yourvalues
> 2. I also would like to compare the testing results of normalized
data
> with the results of raw data (without normalizing the data)? Could I
> just skip the the normalization step as below?
Yes.
Gordon
> group<-paste(L,S,R,sep=".")
> design<-model.matrix(~L+R+S+L:R+L:S+R:S+L:R:S)
> y<-DGEList(counts=counts,group=group)
> #y<-calcNormFactors(y,method="upperquartile",p=0.75) ##skip this
step
>
> y<-estimateGLMCommonDisp(y,design)
> y<-estimateGLMTagwiseDisp(y,design)
>
> fiteUQ_LRS<-glmFit(y,design,offset=offset )
>
> Thanks.
>
>
> Yanzhu
>
>
> -- output of sessionInfo():
>
> sessionInfo()
> R version 3.0.1 (2013-05-16)
> Platform: x86_64-w64-mingw32/x64 (64-bit)
>
> locale:
> [1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United
States.1252 LC_MONETARY=English_United States.1252
> [4] LC_NUMERIC=C LC_TIME=English_United
States.1252
>
> attached base packages:
> [1] parallel stats graphics grDevices utils datasets
methods base
>
> other attached packages:
> [1] DESeq_1.12.1 lattice_0.20-15 locfit_1.5-9.1
Biobase_2.20.1 BiocGenerics_0.6.0 edgeR_3.2.4 limma_3.16.8
>
> loaded via a namespace (and not attached):
> [1] annotate_1.38.0 AnnotationDbi_1.22.6 DBI_0.2-7
genefilter_1.42.0 geneplotter_1.38.0 grid_3.0.1
> [7] IRanges_1.18.4 RColorBrewer_1.0-5 RSQLite_0.11.4
splines_3.0.1 stats4_3.0.1 survival_2.37-4
> [13] XML_3.98-1.1 xtable_1.7-1
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