Plot: fix gridspec syntax for multiple experiments on one plot.

dstat_interface/experiments/experiment_template.py

@@ -282,7 +282,7 @@ class PlotBox(object):
         # Calculate size of grid needed
         
         if len(self.plotnames) > 1:
-            gs = gridspec.GridSpec(ceil(len(self.plotnames)/2.),2)
+            gs = gridspec.GridSpec(int(ceil(len(self.plotnames)/2.)),2)
         else:
             gs = gridspec.GridSpec(1,1)
         for n, i in enumerate(self.plotnames):