Running the Pipeline

From the Command Line

Individual steps and pipelines (consisting of a series of steps) can be run from the command line using the strun command:

$ strun <pipeline_name or class_name> input_file

The first argument to strun must be one of either a pipeline name, python class of the step or pipeline to be run. The second argument to strun is the name of the input data file to be processed. For a list of all the options available for strun, please read the STPIPE Documentation.

For example, the exposure level pipeline is implemented by the class romancal.pipeline.ExposurePipeline. The command to run this pipeline is:

$ strun romancal.pipeline.ExposurePipeline r0008308002010007027_0019_wfi01_uncal.asdf

Pipeline classes also have a pipeline name, or alias, that can be used instead of the full class specification. For example, romancal.pipeline.ExposurePipeline has the alias roman_elp and can be run as

$ strun roman_elp r0008308002010007027_06311_0019_WFI01_uncal.asdf

The mosaic level pipeline can be run in a similar manner and is implemented using the class romancal.pipeline.MosaicPipeline. The command to run this pipeline is:

$ strun romancal.pipeline.MosaicPipeline r0008308002010007027_asn.json

An important point is that the mosaic level pipeline needs multiple exposures to run correctly. The most convenient method to supply the input is to use an association. Instructions on how to create an input association an be found at asn_from_list.

The mosaic level pipeline also has an alias, roman_mos, and can be run as

$ strun roman_mos r0008308002010007027_asn.json

Note

When using an alias with strun (for example strun resample) you may need to provide the romancal package name if you have other packages installed that also use the same alias. The package name is provided prior to the alias separated by :: (for example strun romancal::resample).

Exit Status

strun produces the following exit status codes:

• 0: Successful completion of the step/pipeline

• 1: General error occurred

From the Python Prompt

You can execute a pipeline or a step from within python by using the call method of the class. This creates a new instance of the class and runs the pipeline or step.

The call method creates a new instance of the class and runs the pipeline or step. Optional parameter settings can be specified by via keyword arguments or supplying a parameter file. Some examples are shown below.

For the exposure pipeline and steps,

from romancal.pipeline import ExposurePipeline
result = ExposurePipeline.call('r0000101001001001001_0001_wfi01_uncal.asdf')

from romancal.linearity import LinearityStep
result = LinearityStep.call('r0000101001001001001_0001_wfi01_uncal.asdf')

One difference between the mosaic level pipeline and the exposure level pipeline is that the mosaic level pipeline is generally designed to run on multiple overlapping exposures. To achieve that the input to the pipeline is a list of images, usually an association. For the mosaic level pipeline and steps,

from romancal.pipeline import MosaicPipeline
result = ExposurePipeline.call('r0000101001001001001_asn.json')

from romancal.skymatch import SkyMatchStep
result = SkyMatchStep.call('r0000101001001001001_asn.json')

For more information, see Execute via call()

For details on the different ways to run a pipeline step, see the Configuring a Step page.