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microseq (version 1.3)

plot.Fastq: Plotting and summary of Fastq objects

Description

Generic functions for plotting and printing the content of a Fastq object.

Usage

# S3 method for Fastq
plot(x, y = NULL, col = "tan4", border = "tan4", ...)

# S3 method for Fastq summary(object, ...)

Arguments

x

A Fastq object, see below.

y

not used.

col

Color of bar interiors.

border

Color of bar borders.

...

Optional graphical arguments.

object

A Fastq object, see below.

Details

A Fastq object contains biological sequences in the FASTQ format. It is a small (S3) extension to a data.frame. It is actually a data.frame containing at least three text columns named Header, Sequence and Quality. The Header column contains the headerlines for each sequence, the Sequence columns the sequences themselves and the Quality the base-quality sequence. A Fastq object is typically created by reading a FASTQ formatted file into R by readFastq.

A Fastq object can be treated as a data.frame, which makes it quick and easy to search both for specific regular expressions, sort or re-arrange the ordering of the sequences, extract subsets or add new data to an existing Fastq object.

A Fastq object can also be treated as a Fasta object. Using writeFasta will write the Fastq to a file in Fasta format.

The plot.Fastq function will display the content of the Fastq object as a histogram over the lengths of the sequences.

The summary.Fastq function will display a text giving the number of sequences and the alphabet, i.e. listing all unique symbols found in the file.

See Also

readFastq, writeFastq.

Examples

Run this code
# NOT RUN {
# See the examples in the Help-file for readFastq/writeFastq

# }

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