Adding handling for nan values in eff_distance

gstlal wants to set eff_distance to nan when they don't have a
meaningful value for it.  Unfortunately, we can't save that in the
database because MySQL numeric types can't deal with nans. So we
check for nans in this field and set it to NULL if it is nan,
before saving it in the database.

gracedb/events/models.py

+from math import isnan
+
 from django.db import models, IntegrityError
 from django.urls import reverse
 
@@ -986,12 +988,17 @@ class SingleInspiral(models.Model):
             #log.debug("Single/creating event")
             for f in [cls._meta.get_field(f) for f in cls.field_names()]:
                 value = getattr(row, f.attname, f.default)
+
+                # Handle nan for eff_distance
+                if f.attname == 'eff_distance' and isnan(value):
+                    value = None
+
                 # Only set value of class instance member if
                 # value is not None or if field is nullable.
                 # Otherwise we could overwrite non-nullable fields
                 # which have default values with None.
                 if value is not None or f.null:
-                    #log.debug("Setting column '%s' with value '%s'" % (column, value))
+                    #log.debug("Setting column '%s' with value '%s'" % (f.attname, value))
                     setattr(e, f.attname, value)
             e.save()
             created_events.append(e)

gracedb/templates/gracedb/event_detail_coinc.html

@@ -93,7 +93,11 @@
 	<tr>
 		<th>Effective Distance</th>
 		{% for e in single_inspiral_events %}
-		<td>{{ e.eff_distance }}&nbsp;Mpc</td>
+        <td>
+        {% if e.eff_distance %}
+		{{ e.eff_distance }}&nbsp;Mpc
+        {% endif %}
+        </td>
 		{% endfor %}
 	</tr>
 	<tr>