Fix indexing in xdmf jinja template

Author: xylar

conda_package/mpas_tools/viz/mpas_to_xdmf/templates/xdmf_template.xml

@@ -3,9 +3,9 @@
   <Domain>
     <Grid Name="TimeSeries" GridType="Collection" CollectionType="Temporal">
       {% if times|length > 0 %}
-      {% set t_index = 0 %}
-      {% for t_val in times %}
-      <Grid Name="Step{{ t_index }}" GridType="Uniform">
+    {% for t_val in times %}
+    {% set t_index = loop.index0 %}
+    <Grid Name="Step{{ t_index }}" GridType="Uniform">
         <Time Value="{{ t_val }}"/>
         <Topology TopologyType="Polygon" NumberOfElements="{{ num_elements }}" NodesPerElement="{{ num_verts }}">
           <DataItem Format="HDF" Dimensions="{{ num_elements }} {{ num_verts }}">{{ h5_basename }}:/Cells</DataItem>
@@ -16,7 +16,7 @@
         {% for var in variables %}
         {% if var.has_time %}
         <Attribute Name="{{ var.name }}" AttributeType="Scalar" Center="Cell">
-          <DataItem Format="HDF" Dimensions="{{ num_elements }}">{{ h5_basename }}:/{{ var.name }}_t{{ t_index }}</DataItem>
+      <DataItem Format="HDF" Dimensions="{{ num_elements }}">{{ h5_basename }}:/{{ var.name }}_t{{ t_index }}</DataItem>
         </Attribute>
         {% else %}
         <Attribute Name="{{ var.name }}" AttributeType="Scalar" Center="Cell">
@@ -25,7 +25,6 @@
         {% endif %}
         {% endfor %}
       </Grid>
-      {% set t_index = t_index + 1 %}
       {% endfor %}
       {% else %}
       <Grid Name="Static" GridType="Uniform">