Hi Michael,
The supplemental file 3 in the manuscript is not available yet. I was
told it will be available in a week or so. I will try to rerun the
test with blind set as TRUE.
Shucong
On Nov 27, 2013, at 3:13 PM, Michael Love
<michaelisaiahlove@gmail.com> wrote:
> hi Shucong,
>
> I'm replying and including the Bioconductor list.
>
> It depends on what you mean by 'not working', I see that the plots
of standard deviation over mean are not flat using the two
transformations from DESeq2. For both transformations, you are
specifying blind=FALSE, which means that the group means are taken
into consideration when estimating the dispersion-mean relationship.
Then for the plot, you are calculating the standard deviation over all
the samples, regardless of groups. I would say that the plot does not
imply that the transformation did not work, as the dispersion-mean
relationship was not calculated with respect to inter-group
differences because 'blind' was set to FALSE. I can't tell if the
manuscript you reference used blind dispersion estimation or not when
they were using the VST (I couldn't find a link to supplemental file
3).
>
> hope this helps,
>
> Mike
>
> On Wed, Nov 27, 2013 at 3:21 PM, Shucong Li
<shucong.li@umanitoba.ca> wrote:
> Hello Dr. Love,
>
> I tried to used DESeq2 to do VST transformation with my NGS
(bacterial 16srRNA based) data. I came to this approach after I read
the manuscript written by Profs McMurdie and Holmes titled "Waste Not,
Want Not: Why Rarefying Microbiome Data Is Inadmissible". However,
the VST transformation did work as what suggested in the Vignettes. I
started wondering this VST from DESeq2 may not work to my data. I
emailed Prof. Holmes this morning to get her opinion. By the mean
time, it would be great i can have your opinion regarding this issue.
>
> I also attached the R codes and data (R workspace file).
>
> Thank you in advance.
>
> Shucong
>
>
>
>
> Shucong Li PhD Research Associate
> -----------------------------------
> Department of Animal Science
> University of Manitoba
> 12 Dafoe Rd, Winnipeg, Manitoba
> R3T 2N2, Canada
>
> Tel: (204) 474 9841
> Fax: +1(204) 474 7628
> Email: shucong.li@ad.umanitoba.ca
> -----------------------------------
>
>
>
> dds <- DESeq(dds, fitType="local)
>
>
>
> # ddsClean <- replaceOutliersWithTrimmedMean(dds)
>
> # ddsClean <- DESeq(ddsClean,fitType="local")
>
>
>
> plotDispEsts(dds)
>
>
>
> rld <- rlogTransformation(dds, blind=FALSE)
>
> vsd <- varianceStabilizingTransformation(dds, blind=FALSE)
>
>
>
>
>
> library("vsn")
>
> par(mfrow=c(1,3))
>
> notAllZero <- (rowSums(counts(dds))>0)
>
> meanSdPlot(log2(counts(dds,normalized=TRUE)[notAllZero,] + 1),
>
> ylim = c(0,2.5))
>
> meanSdPlot(assay(rld[notAllZero,]), ylim = c(0,2.5))
>
> meanSdPlot(assay(vsd[notAllZero,]), ylim = c(0,2.5))
>
>
>
>
>
> par(mfrow=c(1,2))
>
> dist <- dist(t(assay(rld)))
>
> fit <- hclust(dist, method="average")
>
> plot(fit, labels=dds@colData$treat)
>
>
>
> dists <- dist(t(assay(vsd)))
>
> fit <- hclust(dists, method="average")
>
> plot(fit, labels=dds@colData$treat)
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