Fit the Purity RB results to an exponential curve.

Use the data to construct guess values for the fits.

Puts the results into a list of fit dictionaries where each dictionary corresponds to a pattern and has fields:

  • params - three parameters of rb_fit_fun. The middle one is the exponent.

  • err - the error limits of the parameters.

  • epc - Error per Clifford.

  • pepc - Purity Error per Clifford.