ploidy_analysis_using_ploidyngs

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https://github.com/diriano/ploidyNGS

Note that you will need a sorted bam file to run ploidyNGS

Script for running a ploidyNGS analysis on perun

#!/bin/bash\\
#$ -S /bin/bash\\
. /etc/profile\\
#$ -cwd

source activate ploidyNGS-preq

/scratch2/software/ploidyNGS/ploidyNGS.py \
    -o outputfilename \
    -b nameofsortedbamfile.bam 

conda deactivate

Perun will immediately generate error messages that look dire if not fatal

“fatal: not a git repository (or any parent up to mount point /misc) Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).”

This is the result of a python function defined by ploidyNGS to try to identify which version of the script you are running, but it typically doesn't work. You can safely ignore these and the program continues to run

One of the options you will be interested in is -d or –max_depth, which is set to 100 by default.

Max number of reads kepth at each position in the reference genome (integer, default: 100)

This sets the maximum read depth ploidyNGS.py will read until it moves on to the next alignment position. For example, if you have it set to a 100, but at position 123 you have actually 500 reads mapped, it will only load the basecalls of the first 100 reads to calculate allele frequencies from. I (Joran) found that it is pretty safe to increase this value to say 2000, to use as much information as possible.

Examine the tab output file. In particular, if the lines for Third and Fourth contain almost all 0.00 then they should be removed from the tab file, otherwise they mess up the histogram.

To see the sorted content of the Third and Fourth lines

grep Fourth myoutput.tab |cut -f4 |sort -n
grep Third myoutput.tab |cut -f4 |sort -n

To remove Third and Fourth lines from the tab

grep -v Fourth myoutput.tab |grep -v Third > mytabforhistogram.tab

Once satisfied with the tab you need to make a pdf (it is suppose to generate it automatically but it doesn't)

On the commandline

 Rscript --vanilla /scratch2/software/ploidyNGS/ploidyNGS_generateHistogram.R mytabforhistogram.tab

This will generate a pdf called NA which you can transfer to your home computer to look at.

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