can't convert to FixedPoint: None

[kalok87]

Traceback (most recent call last):
File "/home/kalok/topographica/topographica", line 17, in
process_argv(sys.argv[1:])
File "/home/kalok/topographica/topo/misc/commandline.py", line 758, in process_argv
execfile(filename,main.dict)
File "/home/kalok/Documents/map_sim/task_142/stevens.jn13/gcal.ty", line 323, in
data = measure_or_pref()
File "/home/kalok/topographica/external/param/param/parameterized.py", line 1847, in new
return inst.call(_args,__params)
File "/home/kalok/topographica/external/featuremapper/featuremapper/command.py", line 123, in call
pattern_response_fn=p.pattern_response_fn)
File "/home/kalok/topographica/external/param/param/parameterized.py", line 1847, in new
return inst.call(_args,*_params)
File "/home/kalok/topographica/external/featuremapper/featuremapper/init.py", line 485, in call
results = self._collate_results(p)
File "/home/kalok/topographica/external/featuremapper/featuremapper/init.py", line 554, in _collate_results
label=name, group=map_label)
File "/home/kalok/topographica/external/holoviews/holoviews/core/ndmapping.py", line 707, in init
super(UniformNdMapping, self).init(initial_items, *_params)
File "/home/kalok/topographica/external/holoviews/holoviews/core/ndmapping.py", line 115, in init
self._add_item(initial_items[0], initial_items[1])
File "/home/kalok/topographica/external/holoviews/holoviews/core/ndmapping.py", line 158, in _add_item
dim_vals = tuple(v if None in [t, v] else t(v) for t, v in dim_types)
File "/home/kalok/topographica/external/holoviews/holoviews/core/ndmapping.py", line 158, in
dim_vals = tuple(v if None in [t, v] else t(v) for t, v in dim_types)
File "/home/kalok/topographica/topo/misc/fixedpoint.py", line 338, in cmp
xn, yn, p = _norm(self, other, FixedPoint=type(self))
File "/home/kalok/topographica/topo/misc/fixedpoint.py", line 504, in _norm
y = FixedPoint(y, x.p)
File "/home/kalok/topographica/topo/misc/fixedpoint.py", line 258, in init
raise TypeError("can't convert to FixedPoint: " + value)
TypeError: can't convert to FixedPoint: None

Hallo, I just try to run my simulation and then I got this error. What is this problem and how can I fix it? I really need some helps, thank you!

[philippjfr]

Do you have gmpy installed?