basis_from_basis not working with compound bases

[theolewy]

When a compound basis x (formed from d domains) is inputted the outputted basis is not of size factor*(x.base_grid_size), but rather d * factor * (x.base_grid_size).

I think this is resolved when n_hi is moved into the for loop like this:

def basis_from_basis(basis, factor):
"""duplicates input basis with number of modes multiplied by input factor.

the new number of modes will be cast to an integer

inputs
------
basis : a dedalus basis
factor : a float that will multiply the grid size by basis

"""
basis_type = basis.__class__.__name__

if type(basis) == de.Compound:
    sub_bases = []
    for sub_basis in basis.subbases:
        sub_basis_type = sub_basis.__class__.__name__
        try:
            n_hi = int(sub_basis.base_grid_size * factor)
            nb = bases_register[sub_basis_type](basis.name, n_hi, interval=sub_basis.interval)
        except KeyError:
            raise KeyError("Don't know how to make a basis of type {}".format(basis_type))
        sub_bases.append(nb)
    new_basis = de.Compound(basis.name, tuple(sub_bases))
else:
    try:
        n_hi = int(basis.base_grid_size * factor)
        new_basis = bases_register[basis_type](basis.name, n_hi, interval=basis.interval)
    except KeyError:
        raise KeyError("Don't know how to make a basis of type {}".format(basis_type))

return new_basis

Sorry if I've got this wrong, but this seems to fix the problem for my code!!