add exception for out of range 'insets.cell'

Author: etpinard

plotly/tools.py

@@ -955,6 +955,14 @@ def _add_domain_is_3d(layout, s_label, x_domain, y_domain):
             r = inset['cell'][0] - 1
             c = inset['cell'][1] - 1
 
+            # Throw exception if r | c is out of range
+            if not (0 <= r < rows):
+                raise Exception("Some 'cell' row value it out of range. "
+                                "Note: the starting cell is (1, 1)")
+            if not (0 <= c < cols):
+                raise Exception("Some 'cell' col value it out of range. "
+                                "Note: the starting cell is (1, 1)")
+
             # Get inset x domain using grid
             x_s = grid[r][c][0] + inset['l'] * width
             if inset['w'] == 'to_end':