maximum_inundation_from_sww test failing in windows

[duncan]

maximum_inundation_from_sww test failing in windows.

I think the changeset:4862 broke this. Could you fix this one Ole? The values of runup & maximal_runup are both None.

ERROR: test_get_maximum_inundation_from_sww(self)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "shallow_water\test_shallow_water_domain.py", line 1286, in test_get_maxi
mum_inundation_from_sww
    q = get_maximum_inundation_elevation('runup_test.sww')
  File "X:\anuga_core\source\anuga\shallow_water\data_manager.py", line 5512, in
 get_maximum_inundation_elevation
    verbose=verbose)
  File "X:\anuga_core\source\anuga\shallow_water\data_manager.py", line 5724, in
 get_maximum_inundation_data
    if runup > maximal_runup:
TypeError: function not supported for these types, and can't coerce to supported
 types

[ole]

This was fixed in changeset:4863

The algorithm exploits the fact that x >= None evaluates to True and x < None evaluates to False for all numerical values of x.

However, the problem was that the only proper floats (or ints) can be compared to None - not the single precision values that have been reinstated in the sww file.

It has now been fixed by converting the arrays to Float (double precision) when read from the sww file.