metaseqR (version 1.12.2)

read.targets: Creates sample list and BAM/BED file list from file

Description

Create the main sample list and determine the BAM/BED files for each sample from an external file.

Usage

read.targets(input, path = NULL)

Arguments

input

a tab-delimited file structured as follows: the first line of the external tab delimited file should contain column names (names are not important). The first column MUST contain UNIQUE sample names. The second column MUST contain the raw BAM/BED files WITH their full path. Alternatively, the path argument should be provided (see below). The third column MUST contain the biological condition where each of the samples in the first column should belong to. There is an optional fourth column which should contain the keywords "single" for single-end reads, "paired" for paired-end reads or "mixed" for BAM files that contain both single- and paired-end reads (e.g. after a mapping procedure with two round of alignment). If this column is not provided, single-end reads will be assumed. There is an optional fifth column which stranded read assignment. It should contain the keywords "forward" for a forward (5'->3') strand library construction protocol, "reverse" for a reverse (3'->5') strand library construction protocol, or "no" for unstranded/unknown protocol. If this column is not provided, unstranded reads will be assumed.

path

an optional path where all the BED/BAM files are placed, to be prepended to the BAM/BED file names in the targets file.

Value

• A named list with four members. The first member is a named list whose names are the conditions of the experiments and its members are the samples belonging to each condition. The second member is like the first, but this time the members are named vectors whose names are the sample names and the vector elements are full path to BAM/BED files. The third member is like the second, but instead of filenames it contains information about single- or paired-end reads (if available). The fourth member is like the second, but instead of filenames it contains information about the strandedness of the reads (if available). The fifth member is the guessed type of the input files (SAM/BAM or BED). It will be used if not given in the main read2count function.

Examples

targets <- data.frame(sample=c("C1","C2","T1","T2"),
    filename=c("C1_raw.bam","C2_raw.bam","T1_raw.bam","T2_raw.bam"),
    condition=c("Control","Control","Treatment","Treatment"))
path <- "/home/chakotay/bam"
write.table(targets,file="~/targets.txt",sep="\t",row.names=FALSE,
    quote=FALSE)
the.list <- read.targets("~/targets.txt",path=path)
sample.list <- the.list$samples
bamfile.list <- the.list$files