DADA2_QUALITY_PROFILES

DADA2 Plotting the quality profile of reads using dada2 plotQualityProfile function. The function is introduced in the dedicated tutorial section.

Example

This wrapper can be used in the following way:

rule dada2_quality_profile_se:
    input:
        # FASTQ file without primers sequences
        "trimmed/{sample}.{orientation}.fastq"
    output:
        "reports/dada2/quality-profile/{sample}.{orientation}-quality-profile.png"
    log:
        "logs/dada2/quality-profile/{sample}.{orientation}-quality-profile-se.log"
    wrapper:
        "v3.8.0/bio/dada2/quality-profile"

rule dada2_quality_profile_pe:
    input:
        # FASTQ file without primers sequences
        expand("trimmed/{{sample}}.{orientation}.fastq",orientation=[1,2])
    output:
        "reports/dada2/quality-profile/{sample}-quality-profile.png"
    log:
        "logs/dada2/quality-profile/{sample}-quality-profile-pe.log"
    wrapper:
        "v3.8.0/bio/dada2/quality-profile"

Note that input, output and log file paths can be chosen freely.

When running with

snakemake --use-conda

the software dependencies will be automatically deployed into an isolated environment before execution.

Software dependencies

• bioconductor-dada2=1.30.0

Input/Output

Input:

• a FASTQ file (potentially compressed) without primers sequences

Output:

• A PNG file of the quality plot

Authors

• Charlie Pauvert

Code

# __author__ = "Charlie Pauvert"
# __copyright__ = "Copyright 2020, Charlie Pauvert"
# __email__ = "cpauvert@protonmail.com"
# __license__ = "MIT"

# Snakemake wrapper for plotting the quality profile of reads using dada2 plotQualityProfile function.

# Sink the stderr and stdout to the snakemake log file
# https://stackoverflow.com/a/48173272
log.file<-file(snakemake@log[[1]],open="wt")
sink(log.file)
sink(log.file,type="message")

library(dada2)

# Plot the quality profile for a given FASTQ file or a list of files
pquality<-plotQualityProfile(unlist(snakemake@input))

# Write the plots to files
library(ggplot2)
ggsave(snakemake@output[[1]], pquality, width = 4, height = 3, dpi = 300)

# Proper syntax to close the connection for the log file
# but could be optional for Snakemake wrapper
sink(type="message")
sink()