Pipeline Commands

DROP is a Snakemake pipeline, so it is called with the snakemake command.

Dry run

Open a terminal in your project repository. Execute

snakemake --cores 1 -n

This will perform a dry-run, which means it will display all the steps (or rules) that need to be executed. To also display the reason why those rules need to be executed, run

snakemake --cores 1 -nr

A simplified dry-run can be achieved using the -q parameter.

snakemake --cores 1 -nq

Calling snakemake --cores 1 without any additional parameters will execute the whole workflow. Snakemake requires you to designate the number of cores.

Parallelizing jobs

DROP’s steps are computationally heavy, therefore it is highly recommended to run them in parallel. Snakemake automatically determines the steps that can be parallelized. The user simply needs to specify the maximum number of cores that Snakemake can take, e.g. for 10 cores:

snakemake --cores 10

Executing subworkflows

Every module can be called independently.

snakemake <subworkflow>

Subworkflow	Description
aberrantExpression	Aberrant expression pipeline
aberrantSplicing	Aberrant splicing pipeline
mae	Monoallelic expression pipeline
sampleQC	DNA-RNA matching (already part of mae, but can be executed independently as well)
rnaVariantCalling	RNA Variant Calling pipeline

For example, to run the aberrant expression pipeline with 10 cores, execute the following

snakemake aberrantExpression --cores 10

Rerunning the pipeline

When DROP is updated or jobs fail, the following commands can be used to rerun and troubleshoot.

Unlocking the pipeline

While running, Snakemake locks the directory. If, for a whatever reason, the pipeline was interrupted, the directory might be kept locked. If this is the case, call

snakemake unlock

Updating DROP

The developers of DROP are active in making DROP a better tool. As a result there are often bug fixes or improvements that are implemented and released in new versions. You can check them out in the What’s new section of the README.

When updating DROP we recommend using the conda/mamba functions to maintain any dependencies that could be related.

mamba update drop

If you were working with a pip installation of DROP then you would need to reinstall using pip directly from github.

pip install git+https://github.com/gagneurlab/drop.git

Once you have successfully bumped the DROP version to the latest, you will still need to update your project folder. drop update will reset the local project’s Scripts/ directory to match the installed version, so be sure to save any additional scripts or analyses in another location.

To complete your update, you must run the following to get your local directory to match the version:

drop update

Skipping recomputation of files

If the pipeline is interrupted and restarted, it will continue with the last unsuccessful job in the job graph. If a script is updated with minor change, e.g. when calling drop update, all the jobs of the modified script and its downstream steps will be rerun. However, in some cases one might want to keep the intermediate files instead and continue with the missing files. In order to do so, first execute

snakemake <rule> --touch

for whichever rule or module you want to continue the computation. The --touch command touches all output files required by the pipeline that have already been computed. Omitting the rule will lead to accessing the complete pipeline. Afterwards, run

snakemake unlock

Overall, we recommend reading the snakemake documentation for further fine-tuning of the execution.