nanopolish on Biowulf
nanopolish is a software package for signal-level analysis of Oxford Nanopore sequencing data. Nanopolish can calculate an improved consensus sequence for a draft genome assembly, detect base modifications, call SNPs and indels with respect to a reference genome and more
Documentation
Important Notes
- Module Name: nanopolish (see the modules page for more information)
- Multithreaded app (use -t option; not available in all commands)
- Environment variables set
- NANOPOLISH_TESTDATA
- Example files in /usr/local/apps/nanopolish/TEST_DATA
Interactive job
Interactive jobs should be used for debugging, graphics, or applications that cannot be run as batch jobs.
Allocate an interactive session and run the program.
Sample session (user input in bold):
[user@biowulf]$ sinteractive --mem 4g salloc.exe: Pending job allocation 46116226 salloc.exe: job 46116226 queued and waiting for resources salloc.exe: job 46116226 has been allocated resources salloc.exe: Granted job allocation 46116226 salloc.exe: Waiting for resource configuration salloc.exe: Nodes cn3144 are ready for job [user@cn3144 ~]$ module load nanopolish [user@cn3144 ~]$ cp $NANOPOLISH_TESTDATA/* . [user@cn3144 ~]$ tar -xf ecoli_2kb_region.tar.gz [user@cn3144 ~]$ cd ecoli_2kb_region/ [user@cn3144 ~]$ nanopolish index -d fast5_files/ reads.fasta [readdb] indexing fast5_files/ [readdb] num reads: 112, num reads with path to fast5: 112 [user@cn3144 ~]$ nanopolish error: no command provided usage: nanopolish [command] [options] valid commands: --help --version call-methylation eventalign extract getmodel help index methyltrain phase-reads polya scorereads variants vcf2fasta for help on given command, type nanopolish command --help [user@cn3144 ~]$ exit salloc.exe: Relinquishing job allocation 46116226 [user@biowulf ~]$
Batch job
Most jobs should be run as batch jobs.
Create a batch input file (e.g. nanopolish.sh). For example:
#!/bin/bash set -e module load nanopolish nanopolish index -d fast5_files/ reads.fasta
Submit this job using the Slurm sbatch command.
sbatch --cpus-per-task=2 --mem=4g nanopolish.sh
Swarm of Jobs
A swarm of jobs is an easy way to submit a set of independent commands requiring identical resources.
Create a swarmfile (e.g. nanopolish.swarm). For example:
nanopolish index -d fast5_files1/ reads1.fasta nanopolish index -d fast5_files2/ reads2.fasta nanopolish index -d fast5_files3/ reads3.fasta
Submit this job using the swarm command.
swarm -f nanopolish.swarm -g 4 -t 2 --module nanopolishwhere
-g # | Number of Gigabytes of memory required for each process (1 line in the swarm command file) |
-t # | Number of threads/CPUs required for each process (1 line in the swarm command file). |
--module nanopolish | Loads the nanopolish module for each subjob in the swarm |