Arguments

The ramp fitting step has the following optional arguments that can be set by the user:

--algorithm: A string to select the desired algorithm. The available values are “OLS” to select the python implementation of the Ordinary Least Squares algorithm, “OLS_C” to select the C extension implementation of OLS, and “LIKELY” to select a prototype maximum-likelihood based approach. The algorithm defaults to “OLS_C”.
--save_opt: A True/False value that specifies whether to write the optional output product. Default is False.
--opt_name: A string that can be used to override the default name for the optional output product.
--int_name: A string that can be used to override the default name for the per-integration product.
--firstgroup, --lastgroup: A pair of integers that can be used to set the first and last groups to be used in the ramp fitting procedure. These values are zero-indexed. If the first group is set to <0, or None, or the last group is set to > (#groups - 1) or None, or the first group is set to > last group, the settings are ignored and the full ramp is fit. Default values for both parameters are None.
--suppress_one_group: A boolean to suppress computations for saturated ramps with only one good (unsaturated) sample. The default is set to True to suppress these computations, which will compute all values for the ramp the same as if the entire ramp were saturated.
--maximum_cores: The number of available cores that will be used for multi-processing in this step. The default value is ‘1’, which results in no multi-processing. Other options are either an integer, ‘quarter’, ‘half’, and ‘all’. Note that these fractions refer to the total available cores and on most CPUs these include physical and virtual cores. The clock time for the step is reduced almost linearly by the number of physical cores used on all machines. For example, on an Intel CPU with six real cores and six virtual cores, setting maximum_cores to ‘half’ results in a decrease of a factor of six in the clock time for the step to run. Depending on the system, the clock time can also decrease even more with maximum_cores set to ‘all’. Setting the number of cores to an integer can be useful when running on machines with a large number of cores where the user is limited in how many cores they can use.