Entering edit mode
Natasha
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440
@natasha-4640
Last seen 10.3 years ago
Dear List,
I am also trying edger on my data (3 groups, 2 reps each). Bacterial
samples.
design
condition pair
1 Cont 1
2 Cont 3
3 Trt1 1
4 Trt1 3
5 Trt2 1
6 Trt2 3
However, when I run the following code: I get a warning message and
wanted to know it's significance in downstream analysis.
----------
y = DGEList(counts=gene.counts, group=group)
str(y)
y$samples
dim(y$counts) #5578 6
keep = rowSums(cpm(y)>10) >= 3
table(keep)
#FALSE TRUE
# 1064 4514
y.filt = y[keep, ]
y.filt$samples$lib.size = colSums(y.filt$counts)
y.filt = calcNormFactors(y.filt)
## Design Matrix
design = model.matrix(~pair+group)
colnames(design) = gsub("group","",colnames(design))
design
## Estimating Dispersion
y.filt = estimateGLMCommonDisp(y.filt, design, verbose=T)
#Disp = 0.03799 , BCV = 0.1949
y.filt = estimateGLMTrendedDisp(y.filt,design)
#Warning message:
#In binGLMDispersion(y, design, min.n = min.n, offset = offset, method
= method.bin, :
# With 4514 genes and setting the parameter minimum number (min.n) of
genes per bin to 500, there are only 5 bins. Using 5 bins here means
that the minimum number of genes in each of the 5 bins is in fact 515.
This number of bins and minimum number of genes per bin may not be
sufficient for reliable estimation of a trend on the dispersions.
y.filt = estimateGLMTagwiseDisp(y.filt,design)
--------------
sessionInfo()
R version 2.15.2 (2012-10-26)
Platform: x86_64-pc-linux-gnu (64-bit)
locale:
[1] LC_CTYPE=en_GB.UTF-8 LC_NUMERIC=C
[3] LC_TIME=en_GB.UTF-8 LC_COLLATE=en_GB.UTF-8
[5] LC_MONETARY=en_GB.UTF-8 LC_MESSAGES=en_GB.UTF-8
[7] LC_PAPER=C LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] splines stats graphics grDevices utils datasets
methods
[8] base
other attached packages:
[1] gdata_2.12.0 WriteXLS_2.3.0 edgeR_2.6.10 limma_3.14.3
loaded via a namespace (and not attached):
[1] gtools_2.7.0
-------
Any help, suggestion and advice much appreciated.
Many Thanks,
Natasha