The goal of fragCounter is to correct Whole genome or targeted sequencing data for GC and mappability bias.
The GC bias curve is determined by loess regression of read count by GC and mappability scores.
Segmentation is done by circular binary segmentation (CBS) algorithm after getting tumor/normal ratios of corrected read counts.
- Install devtools from CRAN (if you don't have it already)
install.packages('devtools')
- Install fragCounter
devtools::install_github('mskilab/fragCounter')
(after installing R package) Add fragCounter directory to PATH and test the executable
$ export PATH=${PATH}:$(Rscript -e 'cat(paste0(installed.packages()["fragCounter", "LibPath"], "/fragCounter/extdata/"))')
$ frag -h ## to see the help message
$ ./frag -b inst/extdata/chr21.bam -d inst/extdata/gcMAP21/ -w 200
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Calling samtools view -f 0x02 -F 0x10 inst/extdata/chr21.bam -q 1 | cut -f "3,4,9"
Starting fragment count on inst/extdata/chr21.bam and min mapQ 1 and insert size limit 10000
Finished computing coverage, and making GRanges
Finished acquiring coverage
Loaded GC and mappability
length cov is 314827, length gc is 3663, length map is 3663
Synced coverage, GC, and mappability
Modified gc / mappability correction
Converting to data.table
Converting to GRanges
Made GRanges
$ ./frag -h
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Usage: ./frag [options]
Options:
-b BAM, --bam=BAM
Path to .bam file
-c COV, --cov=COV
Path to existing coverage rds or bedgraph
-m MIDPOINT, --midpoint=MIDPOINT
If TRUE only count midpoint if FALSE then count bin footprint of every fragment interval
-w WINDOW, --window=WINDOW
Window / bin size
-d GCMAPDIR, --gcmapdir=GCMAPDIR
Mappability / GC content dir
-q MINMAPQ, --minmapq=MINMAPQ
Minimal map quality
-p PAIRED, --paired=PAIRED
Is paired
-e EXOME, --exome=EXOME
Use exons as bins instead of fixed window
-u USE.SKEL, --use.skel=USE.SKEL
Use user defined regions instead of default exome skeleton
-s SKELETON, --skeleton=SKELETON
Path to skeleton file
-o OUTDIR, --outdir=OUTDIR
Directory to dump output into
-l LIBDIR, --libdir=LIBDIR
Directory containing this R file
-h, --help
Show this help message and exit
These can be used as inputs to fragCounter to correct GC and Mappability biases. Make sure to save them in same directory and supplying the path to the directory. Retain the name of the file.
GC file: http://mskilab.com/dryclean/hg19/gc1000.rds
Mappability file: http://mskilab.com/dryclean/hg19/map1000.rds