Relax-fit script mode - optimisation of exponential curves

Now that everything has been setup minimisation can be used to optimise the parameter values. Firstly a grid search is applied to find a rough starting position for the subsequent optimisation algorithm. Eleven increments per dimension of the model (in this case the two dimensions { Rx, I0}) is sufficient. The user function for executing the grid search is

# Grid search.

The next step is to select one of the minimisation algorithms to optimise the model parameters

# Minimise.
minimise.execute('newton', constraints=False)

The relax user manual (PDF), created 2016-10-28.