Specifying Totals for a date dimension is raising an exception

[mikeengland]

Example call:
res = slicer.highcharts.line_chart( metrics=['clicks'], dimensions=['date'], dimension_filters=[RangeFilter('date', date.today() - timedelta(days=14), date.today())], operations=[Totals('date')] )

Traceback (most recent call last): operations=[Totals('date')] File "/lib/python3.4/site-packages/fireant/slicer/managers.py", line 279, in _get_and_transform_data return tx.transform(df, display_schema) File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 47, in transform series = self._make_series(data_frame, dim_ordinal, display_schema) File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 90, in _make_series for idx, item in data_frame.iteritems()] File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 90, in <listcomp> for idx, item in data_frame.iteritems()] File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 95, in _make_series_item 'data': self._format_data(item), File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 168, in _format_data for key, value in column.iteritems() File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 169, in <listcomp> if not np.isnan(value)] File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 173, in _format_point return (_format_data_point(x), _format_data_point(y)) File "/lib/python3.4/site-packages/fireant/slicer/transformers/highcharts.py", line 13, in _format_data_point if np.isnan(value): TypeError: ufunc 'isnan' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe'