# Step Arguments¶

The persistence step has three step-specific arguments.

• --input_trapsfilled

input_trapsfilled is the name of the most recent trapsfilled file for the current detector. If this is not specified, an array of zeros will be used as an initial value. If this is specified, it will be used to predict persistence for the input science file. The step writes an output trapsfilled file, and that could be used as input to the persistence step for a subsequent exposure.

• --flag_pers_cutoff

If this floating-point value is specified, pixels that receive a persistence correction greater than or equal to flag_pers_cutoff DN (the default is 40) are flagged in the PIXELDQ array of the output file with the DQ value “PERSISTENCE”.

• --save_persistence

If this boolean parameter is specified and is True (the default is False), the persistence that was subtracted (group by group, integration by integration) will be written to an output file with suffix “_output_pers”.