Filtering a set of results obtained from job manager

Question

I've already generated a filter for readout error mitigation:

cal_results = cal_job.result()
meas_fitter = CompleteMeasFitter(cal_results, state_labels)  
fig, ax = plt.subplots(figsize=(10, 10))
meas_fitter.plot_calibration(ax)
meas_filter = meas_fitter.filter

I have a set of circuits executed using the IBM job manager, the list is called all_circuits. After transpling the list, I tried:

MExperiments = job_manager.run(all_circuits, backend=backend, shots = nshots)
results = MExperiments.results() 
**mitigated_results = meas_filter.apply(results)**

I'm hoping to use the filter to mitigate the errors for each circuit in the list, but the last line doesn't quite work. It shows me

QiskitError: 'Unrecognized type for raw_data.'

How can I fix this issue? Thanks:)

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PS: From the tutorial, there're 4 types of raw data that match the requirement:

Form1: A counts dictionary from results.get_counts,

Form2: A list of counts of length=len(state_labels),

Form3: A list of counts of length=M*len(state_labels) where M is an integer (e.g. for use with the tomography data),

Form4: A qiskit Result.

I'm not pretty sure why the results in my code doesn't fit any one of them.

Answer 1

As mentioned above, there're 4 types of data that match the requirement. The results in this case obtained from the job manager is not the same as the results shown in the tutorial since it contains a set of results from different quantum circuits. (I'm still confused why this is not considered as a qiskit result, i.e Form 4 above.)

As I tried to print the type, it shows meqiskit.providers.ibmq.managed.managedresults.ManagedResults . Then I searched more information from here. There's a method called combine_results() that allows us to combine results from all jobs into a single Result, which is the same result in the tutorial's example. So I just did:

MExperiments = job_manager.run(all_circuits, backend=backend, shots = nshots)
results = MExperiments.results() 
cresults = results.combine_results()
mitigated_results = meas_filter.apply(cresults)