adapted to new holoviews syntax

DataModule/data_grid.py

@@ -267,8 +267,11 @@ class data_grid(data_module_base):
             y_vals = self.df.dims[1]
         else:
             y_vals = name_y
-        hv.opts({mode: {'plot': {'width': width, 'height': height},
-                              'style': {'cmap': cmap}}})
+        hv.opts.defaults(hv.opts.Image(
+            width=width,
+            height=height,
+            cmap=cmap
+        ))
         # Rename z values (to prevent bug in holoviews)
         df = self.df[self.x_min:self.x_max, self.y_min:self.y_max].rename('z')
         # Create dataset