datafile: allow single-point domain size in some direction

Used in cartoon configurations.

1 files changed, 4 insertions, 1 deletions

diff --git a/datafile.py b/datafile.py
index b7e437b..0436e2a 100644
--- a/datafile.py
+++ b/datafile.py
@@ -136,7 +136,10 @@ class _DataSet(object):
         # get the spatial step sizes
         step = [None] * nb_dims
         for i in range(nb_dims):
-            step[i] = abs(data[0].layout.coords[i][1] - data[0].layout.coords[i][0])
+            if len(data[0].layout.coords[i]) > 1:
+                step[i] = abs(data[0].layout.coords[i][1] - data[0].layout.coords[i][0])
+            else:
+                step[i] = 1.0
 
         # calculate the extents of the result
         coord_max = [None] * nb_dims