Entering edit mode
Jarek Bryk
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110
@jarek-bryk-3457
Last seen 10.2 years ago
Hello,
I am trying to analyse my two-color mouse aCGH data on Agilent
platform. I have custom-designed 1M probe CGH arrays for which I have
a xml file that defines the arrays' design (layout etc.). My goal (for
now) is to identify CNVs in the samples. I am trying to use snapCGH to
analyse the samples, but I stumble upon some basic preprocessing
steps.
I can read in the Feature Extraction files with no problem (following
almost literally snapCGH user guide, just for single sample):
> RG1<-read.maimages(file="sample1.txt",source="agilent")
Read sample1.txt
> str(RG1)
Formal class 'RGList' [package "limma"] with 1 slots
..@ .Data:List of 8
.. ..$ : num [1:974016, 1] 297 33.6 35.2 145.7 333.7 ...
.. .. ..- attr(*, "dimnames")=List of 2
.. .. .. ..$ : NULL
.. .. .. ..$ : chr "sample1"
.. ..$ : num [1:974016, 1] 25 25 25 25 25 25 25 25 25 25 ...
.. .. ..- attr(*, "dimnames")=List of 2
.. .. .. ..$ : NULL
.. .. .. ..$ : chr "sample1"
.. ..$ : num [1:974016, 1] 333.8 78.2 54.7 111.8 170.5 ...
.. .. ..- attr(*, "dimnames")=List of 2
.. .. .. ..$ : NULL
.. .. .. ..$ : chr "sample1"
.. ..$ : num [1:974016, 1] 52 52 52 53 53 53 53 53 53 52 ...
.. .. ..- attr(*, "dimnames")=List of 2
.. .. .. ..$ : NULL
.. .. .. ..$ : chr "sample1"
.. ..$ :'data.frame': 1 obs. of 1 variable:
.. .. ..$ FileName: chr "sample1"
.. ..$ :'data.frame': 974016 obs. of 9 variables:
.. .. ..$ Row : int [1:974016] 1 1 1 1 1 1 1 1 1 1 ...
.. .. ..$ Col : int [1:974016] 1 2 3 4 5 6 7 8 9 10 ...
.. .. ..$ Start : int [1:974016] 0 0 0 0 0 0 0 0 0 0 ...
.. .. ..$ Sequence : chr [1:974016] "" "" ""
"CCCATTCACTAATCTACATATTATCTCCATCCAACAAAAATTTCTTTCAGTAAGGTGTGG" ...
.. .. ..$ ProbeUID : int [1:974016] 0 1 1 3 5 7 9 11 13 15 ...
.. .. ..$ ControlType : int [1:974016] 1 1 1 0 0 0 0 0 0 0 ...
.. .. ..$ ProbeName : chr [1:974016] "MmCGHBrightCorner"
"DarkCorner" "DarkCorner" "A_67_P21917383" ...
.. .. ..$ GeneName : chr [1:974016] "MmCGHBrightCorner"
"DarkCorner" "DarkCorner" "Msn" ...
.. .. ..$ SystematicName: chr [1:974016] "MmCGHBrightCorner"
"DarkCorner" "DarkCorner" "chrX:93323379-93323438" ...
.. ..$ : chr "agilent"
.. ..$ :List of 4
.. .. ..$ ngrid.r: num 1
.. .. ..$ ngrid.c: num 1
.. .. ..$ nspot.r: int 1068
.. .. ..$ nspot.c: int 912
> RG1$design<- -1 # I have flipped data where red is the reference
> RG2<-backgroundCorrect(RG1,method="normexp")
Array 1 corrected
Array 1 corrected
> MA<-normalizeWithinArrays(RG2,method="loess")
And after this command I think I need to supply the design file to
limma/snapCGH so that it knows what to do with processCGH or
genomePlot, because this happens during the next steps:
> MA2<-processCGH(MA, method.of.averaging=mean,ID="ProbeUID")
Error in order(MA$genes$Chr, MA$genes$Position) :
argument 1 is not a vector
> genomePlot(MA,array=1)
Error in order(datainfo$Chr, datainfo$Position) :
argument 1 is not a vector
I am shooting in the dark with the ProbeUID field here, as this should
be the unique probe identifier, but it's not where the problem is. I
need position of genes in the genome, and this is in the design file.
I think I should use the readPositionalInfo to relay this information
to limma/snapCGH, but it only accepts objects of class RGList or
MAList, and my design is an xml file - I don't know how to parse the
file...
I would be very grateful for any clarification on how to proceed with
the analysis.
cheers
jarek
> sessionInfo()
R version 2.12.0 (2010-10-15)
Platform: i386-apple-darwin9.8.0/i386 (32-bit)
locale:
[1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8
attached base packages:
[1] splines stats graphics grDevices utils datasets
methods base
other attached packages:
[1] snapCGH_1.20.0 DNAcopy_1.24.0 limma_3.6.0 aCGH_1.28.0
multtest_2.6.0 Biobase_2.10.0
[7] survival_2.35-8 cluster_1.13.1 GLAD_2.12.0
loaded via a namespace (and not attached):
[1] affy_1.28.0 affyio_1.18.0 annotate_1.28.0
AnnotationDbi_1.12.0
[5] DBI_0.2-5 genefilter_1.32.0 grid_2.12.0
lattice_0.19-13
[9] MASS_7.3-8 preprocessCore_1.12.0 RColorBrewer_1.0-2
RSQLite_0.9-2
[13] strucchange_1.4-2 tilingArray_1.28.0 tools_2.12.0
vsn_3.18.0
[17] xtable_1.5-6
--
Jarek Bryk | www.evolbio.mpg.de/~bryk
Max Planck Institute for Evolutionary Biology
August Thienemann Str. 2 | 24306 Pl?n, Germany
tel. +49 4522 763 287 | bryk at evolbio.mpg.de