function to return fancy index list for pysb parameters

[blakeaw]

It would be good to add a function to SwarmParam which can return the list of indices needed for fancy indexing the set of parameters. The current mask function which returns a boolean mask currently only works if parameters are added to a SwarmParam instance in the same relative order in which they are defined in model.parameters. Having a function to instead return the list of indices for fancy indexing would more easily accommodate adding parameters to SwarmParam out of order. This function accomplishes this task:

def fancy_index(swarm_param, parameters):
    idxs = list()
    for name in swarm_param.names():
        i = 0
        for parm in parameters:
            if parm.name == name:
                idxs.append(i)
                break
            i += 1
    return idxs

So, that can be adapted as a member function to SwarmParam.