Examples

In the examples below, img is either a string with the filename of a Roman ASDF file or a Roman datamodel ImageModel.

1. To run TweakReg in a Python session with the default parameters:

   from romancal.tweakreg.tweakreg_step import TweakRegStep
   step = TweakRegStep()
   step.run([img])
   

   Note

   If the input is a single Roman DataModel, either step.run([img]) or step.run(img) will work. For multiple elements as input, they must be passed in as either a list or a ModelLibrary.

2. To run TweakReg in a Python session on an association file with the default parameters:

   from romancal.tweakreg.tweakreg_step import TweakRegStep
   step = TweakRegStep()
   step.run("asn_file.json")
   

3. To run TweakReg on a Roman’s exposure with default astrometric parameters and save the absolute catalog data:

   from romancal.tweakreg.tweakreg_step import TweakRegStep
   step = TweakRegStep()
   step.save_abs_catalog = True # save the catalog data used for absolute astrometry
   step.abs_refcat = 'GAIADR3' # use Gaia DR3 for absolute astrometry
   step.catalog_path = '/path/for/the/abs/catalog' # save the Gaia catalog to this path
   step.run([img])