The standardisation of error bars must be done on the final estimates, not on the estimates for a single block.

Use a much more readable formula to compute the uncertainties. We use the fact that Var(X) = E(Var(X)) + Var(E(X)). At the same time, broadcast the weights array to the same shape as the other arrays in order to simplify the syntax for the computation.

Add a results manager to store the results of the analysis (bayesian and best fit estimates, best chi², etc.). Several such managers can be merged to combine appropriately the analysis of the observations in different blocks. This is the base class. The implementation will come in subsequent patches.