@@ -137,7 +137,7 @@ class AverageLearner(BaseLearner):

             return hv.Histogram([[], []])

         num_bins = int(max(5, sqrt(self.npoints)))

         vals = hv.Points(vals)

-        return hv.operation.histogram(vals, num_bins=num_bins, dimension=1)

+        return hv.operation.histogram(vals, num_bins=num_bins)

     def _get_data(self):

         return (self.data, self.npoints, self.sum_f, self.sum_f_sq)