User stories for using R within the Compute module

Authors: Danny, Morris, Joeri

User story: adding an R script

How to demo:

Within the user interface you can choose [ComputeProtocol] and then choose [New]. Then you can give the compute protocol a name, set the type to 'R' and in a text box copy your R script.

For example:

Name	OneTraitQtlMapping
Interpreter	R
Script	genotypes <- getFromDb(genotypes_name) phenotypes <- getFromDb(phenotype_name) onetraitqtlmapping(trait_names, genotypes, phenotypes)

Next you define the parameters that you have in your script, which are 'traitname' and 'datasetname' and 'iteration'. These are can be described using ComputeFeature?, where we define them as follows:

Name	Datatype	Description
traitnames	List(String)	This is a list of trait names such as defined in your data set. For example 'height' or 'probe01'
genotypes_name	xref(Data)	This a lookup in the list of available Data so the user can choose the genotypes (implicitly links to map
phenotype_name	xref(Data)	This is a lookup in the list of available Data so the user can choose the phenotypes
results_name	String	This is the name of the new data set that will be created to store the data in (or if it exists, data will be added to it

User story: running an R script

How to demo:

Within the user interface you can choose [Run analyses]. Here you can browse the list of available compute protocols. For example, lets choose the protocol that we defined in the previous user story. Then you are provided with autogenerated input boxes based on the ComputeFeature? that you defined; We fill in the parameters:

traitnames	height,length
genotypes_name	geno
phenotypes_name	classic
results_name	My phenotype qtl profiles

And push [Next].

Automatically a new ComputeApplication is generated that looks as follows.

script =

//sources useful scripts to interact with MOLGENIS
source("path/your/molgenis/instance/source.R")

//autogenerated by MOLGENIS based on your parameters
traitnames <- c("height","length")
genotypes_name <- "geno"
phenotypes_name <- "classic"
results_name <- "My phenotype qtl profiles" //spaces will be removed when storing as file...

//also this includes some useful system parameters
dbPath <-  "xyz"

//below the script as we defined above is copied for full provenance

//I just create any script that works with my parameters
genotypes <- getFromDb(genotypes_name)
phenotypes <- getFromDb(phenotype_name)
onetraitqtlmapping(trait_names, genotypes, phenotypes)

Notice how the parameters are simply passed at the beginning of your script. This means you can just copy-paste this script in you R terminal and it should work there as well as on the cluster (ideal for testing)!

If you again push NEXT? this job will be sent to Job manager (user story TODO).

User story: using R to define large scale analyses

How to demo:

Within the user interface you repeat user story on 'adding an R script'. Goal now is to make a script uses MOLGENIS job submission API to automatically calculate qtl profiles on all our phenotypes. We again choose [New ComputePrococol] and add a script that looks like the following:

//here our script will use the job submission API so you can run many R scripts
for(i in 1:number_of_jobs)
{
        //cut out a subset of the phenotypes
        selectedNames <- sliceList(i,number_of_jobs)

        //define what other job MOLGENIS should call 
	submitJob(command="onetraitqtlmapping", genotypes_name=genotypes_name, phenotypes_name=phenotypes_name, traitnames=selectedNames);

	//Note: all parameters you pass to submitJob will be automatically passed to the other protocol
	//result is that a new "computeapplication" will be created programmatically instead of via the UI to be sent to the cluster
}

Note how we replaced "trait_names" with "number_of_jobs" because we just want to run all phenotypes :-)

Name	Datatype	Description
genotypes_name	xref(Data)	This a lookup in the list of available Data so the user can choose the genotypes (implicitly links to map
phenotype_name	xref(Data)	This is a lookup in the list of available Data so the user can choose the phenotypes
results_name	String	This is the name of the new data set that will be created to store the data in (or if it exists, data will be added to it
number_of_jobs	Integer	This will determine how the phenotype dataset will be split in jobs; should be 1 or larger.

Discussion: we could even decide here to generate a whole R script and pass that as the command. How cool would that be? Than the other protocol doesn't even have to exist in the database.