Determine normalisation factors for a specified set of
samples. Potentially only a subset of the peaks can be used to
determine normalisation factors. The determined factors
can be accessed with DBA$MD$NormFactors. Normalised total counts
are additionally computed and stored at DBA$MD$NormTotalCounts.
currently only the DESeq normalisation method is
implemented [1].
SampleIDs
State which samples should be normalised; if NULL
all are used.
Usefiltered
If TRUE, only peaks that have passed the filter
to detect Outliers are used. findOutlier() must be run first, otherwise all
peaks are used
PeakIDs
Specify a subset of peaks to be used to determine
normalisation factors; If NULL all peaks are used.
overWrite
If TRUE, previous computed NormFactors and
NormTotalCounts are overwritten
Value
DBA object, with additional list elements NormFactors and
NormTotalCounts appended to MD. Note, that if you call
getNormFactors several times with different parameters, you can have
more than one set of normalisation factors appended. However,
NormTotalCounts will be overwritten unless specified otherwise.
Author(s)
Gabriele Schweikert
References
[1] Anders S. and Huber W. (2010).
Differential expression analysis for sequence count data
Genome Biology, 11 (10): R106
See Also
getPeakProfiles,
plotPeak,
findOutliers
Examples
# load DBA objects with peak profiles
data(Cfp1Profiles)
Cfp1Norm <- getNormFactors(Cfp1Profiles)
Cfp1Norm$MD$NormFactors
# compare total counts before and after normalisation:
boxplot(Cfp1Norm$MD$RawTotalCounts[,1:3], ylim=c(0,2000))
boxplot(Cfp1Norm$MD$NormTotalCounts[,1:3], ylim=c(0,2000))
# compare individual peak profiles before and after normalisation,
# using plotPeak, e.g.:
plotPeak(Cfp1Norm, Peak.id=20, NormMethod = NULL)
plotPeak(Cfp1Norm, Peak.id=20, NormMethod = 'DESeq')
# You can also specify a subset of samples which should be normalised, e.g:
SampleIDs <- c("WT.AB2", "Null.AB2")
Cfp1Norm2 <- getNormFactors(Cfp1Profiles, SampleIDs=SampleIDs)
# Or you can specify a subset of peaks which should be used to determine
# the normalisation factors. For example run findOutliers:
Cfp1 <- findOutliers(Cfp1Profiles, range=5)
PeakIDs <- Cfp1$MD$Filter$FiltPeakIds
Cfp1Norm3 <- getNormFactors(Cfp1, PeakIDs = PeakIDs)
Results
R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
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> library(MMDiff)
Loading required package: GenomicRanges
Loading required package: BiocGenerics
Loading required package: parallel
Attaching package: 'BiocGenerics'
The following objects are masked from 'package:parallel':
clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
clusterExport, clusterMap, parApply, parCapply, parLapply,
parLapplyLB, parRapply, parSapply, parSapplyLB
The following objects are masked from 'package:stats':
IQR, mad, xtabs
The following objects are masked from 'package:base':
Filter, Find, Map, Position, Reduce, anyDuplicated, append,
as.data.frame, cbind, colnames, do.call, duplicated, eval, evalq,
get, grep, grepl, intersect, is.unsorted, lapply, lengths, mapply,
match, mget, order, paste, pmax, pmax.int, pmin, pmin.int, rank,
rbind, rownames, sapply, setdiff, sort, table, tapply, union,
unique, unsplit
Loading required package: S4Vectors
Loading required package: stats4
Attaching package: 'S4Vectors'
The following objects are masked from 'package:base':
colMeans, colSums, expand.grid, rowMeans, rowSums
Loading required package: IRanges
Loading required package: GenomeInfoDb
Loading required package: DiffBind
Loading required package: SummarizedExperiment
Loading required package: Biobase
Welcome to Bioconductor
Vignettes contain introductory material; view with
'browseVignettes()'. To cite Bioconductor, see
'citation("Biobase")', and for packages 'citation("pkgname")'.
Loading required package: GMD
Loading required package: Rsamtools
Loading required package: Biostrings
Loading required package: XVector
Warning message:
Package 'MMDiff' is deprecated and will be removed from Bioconductor
version 3.4
> png(filename="/home/ddbj/snapshot/RGM3/R_BC/result/MMDiff/getNormFactors.Rd_%03d_medium.png", width=480, height=480)
> ### Name: getNormFactors
> ### Title: Determine Normalisation factors
> ### Aliases: getNormFactors
>
> ### ** Examples
>
>
> # load DBA objects with peak profiles
>
> data(Cfp1Profiles)
> Cfp1Norm <- getNormFactors(Cfp1Profiles)
Computing Scaling factor according to DESeq normalization method
Using all Samples: nSamples = 3
Samples:
[1] "WT.AB2" "Null.AB2" "Resc.AB2"
Using unfiltered Peaks
nPeaks = 1000 (of 1000)
appending NormTotalCounts
Determined Factors:
$`WT.AB2,Null.AB2,Resc.AB2`
WT_2 Null_2 Resc_2
0.9439729 0.8899213 1.1986945
> Cfp1Norm$MD$NormFactors
$DESeq
$DESeq$`WT.AB2,Null.AB2,Resc.AB2`
WT_2 Null_2 Resc_2
0.9439729 0.8899213 1.1986945
>
> # compare total counts before and after normalisation:
> boxplot(Cfp1Norm$MD$RawTotalCounts[,1:3], ylim=c(0,2000))
> boxplot(Cfp1Norm$MD$NormTotalCounts[,1:3], ylim=c(0,2000))
>
> # compare individual peak profiles before and after normalisation,
> # using plotPeak, e.g.:
>
> plotPeak(Cfp1Norm, Peak.id=20, NormMethod = NULL)
No normalization factors applied
>
> plotPeak(Cfp1Norm, Peak.id=20, NormMethod = 'DESeq')
>
>
>
>
> # You can also specify a subset of samples which should be normalised, e.g:
>
> SampleIDs <- c("WT.AB2", "Null.AB2")
> Cfp1Norm2 <- getNormFactors(Cfp1Profiles, SampleIDs=SampleIDs)
Computing Scaling factor according to DESeq normalization method
Using subset of samples: nSamples = 2 (of 3)
Samples:
[1] "WT.AB2" "Null.AB2"
Using unfiltered Peaks
nPeaks = 1000 (of 1000)
appending NormTotalCounts
Determined Factors:
$`WT.AB2,Null.AB2`
WT_2 Null_2
1.0249705 0.9756378
>
> # Or you can specify a subset of peaks which should be used to determine
> # the normalisation factors. For example run findOutliers:
>
> Cfp1 <- findOutliers(Cfp1Profiles, range=5)
Error in dev.new() : no suitable unused file name for pdf()
Calls: findOutliers -> dev.new
Execution halted