error_summary output can be empty in some cases #10
Description
I am using sdynpy.core.sdynpy_data.PowerSpectralDensityArray.error_summary to compare test data (from a Rattlesnake virtual test) to a CPSD spec. Documentation says it should return a tuple of dictionaries of error metrics.
I am running the following line:
error_metrics = cpsd_spec.error_summary(figure_kwargs={}, linewidth=1, plot_kwargs={}, cpsd_matrices = cpsd_data)
where cpsd_spec and cpsd_data are both PowerSpectralDensityArray objects with shape 10 x 10 and 1000 elements per function. The function does produce the error summary plot (including the dB error vs. frequency), but my error_metrics output is NoneType.
I see in line 1911 of sdynpy_data.py that return_data is initialized as None. If len(cpsd_matrices) > 1 (line 1928), return_data is populated with the error metrics. However, if this boolean returns False, as it does in my case, return_data stays as NoneType. Can a line be added to the len(cpsd_matrices) > 0 case to populate return_data, or is this a problem with my inputs to error_summary()? Thank you!