Note that this task operates in scantable format which is discontinued support from CASA 5.0.  This "old" version is retained to preserve back-consistency. The functionality of this task is replicated for measurements format,  with sdcal

Task sdreduceold performs data selection, calibration, spectral averaging and/or baseline fitting for single-dish spectra. This task internally calls the tasks, sdcal, sdaverage, and sdbaseline and it can be used to run all the three steps in one task execution. This task has better performance than invoking the three tasks separately because it runs all three steps without writing intermediate data to disk. It is possible to skip arbitrary operations by setting calmode = 'none' (for calibration), average=False (for time and polarization averaging), kernel = 'none' (for smoothing), and/or blfunc='none' (for baseline fitting). Please take a look at descriptions of tasks, sdcal, sdaverage, and sdbalseline, for more information.