Reenable combined sky maps now using multi-ordering

This MR both enables the following functionality:

• Create multi-order combined sky maps using the GRB localization to re-weight the GW localization
• Change logic in external_triggers.handle_grb_igwn_alert to create combined sky maps as soon as available
• Include combined sky maps in both GCN notices, GCN circulars, and AVRO alert packets.

gwcelery/tasks/external_skymaps.py

@@ -6,10 +6,10 @@ from celery import group
 #  import astropy.utils.data
 import numpy as np
 from ligo.skymap.io import fits
-from ligo.skymap.tool import ligo_skymap_combine
 import gcn
 import healpy as hp
 import lxml.etree
+from mhealpy import HealpixMap
 import re
 import ssl
 import urllib
@@ -30,28 +30,29 @@ def create_combined_skymap(se_id, ext_id):
     """
     se_skymap_filename = get_skymap_filename(se_id)
     ext_skymap_filename = get_skymap_filename(ext_id)
-    new_skymap_filename = re.findall(r'(.*).fits.gz', se_skymap_filename)[0]
 
-    #  FIXME: put download functions in canvas
-    se_skymap = gracedb.download(se_skymap_filename, se_id)
-    ext_skymap = gracedb.download(ext_skymap_filename, ext_id)
     message = 'Combined LVC-external sky map using {0} and {1}'.format(
         se_skymap_filename, ext_skymap_filename)
     message_png = (
         'Mollweide projection of <a href="/api/events/{graceid}/files/'
         '{filename}">{filename}</a>').format(
-            graceid=se_id, filename=new_skymap_filename + '-ext.fits.gz')
+            graceid=se_id,
+            filename='combined-ext.multiorder.fits')
 
     (
-        combine_skymaps.si(se_skymap, ext_skymap)
+        _download_skymaps.si(
+            se_skymap_filename, ext_skymap_filename, se_id, ext_id
+        )
+        |
+        combine_skymaps.s()
         |
         group(
-            gracedb.upload.s(new_skymap_filename + '-ext.fits.gz', se_id,
+            gracedb.upload.s('combined-ext.multiorder.fits', se_id,
                              message, ['sky_loc', 'public']),
 
             skymaps.plot_allsky.s()
             |
-            gracedb.upload.s(new_skymap_filename + '-ext.png', se_id,
+            gracedb.upload.s('combined-ext.png', se_id,
                              message_png, ['sky_loc', 'ext_coinc', 'public'])
         )
     ).delay()
@@ -69,7 +70,7 @@ def get_skymap_filename(graceid):
     if 'S' in graceid:
         for message in reversed(gracedb_log):
             filename = message['filename']
-            if filename.endswith('.fits.gz'):
+            if filename.endswith('.multiorder.fits'):
                 return filename
     else:
         for message in reversed(gracedb_log):
@@ -81,17 +82,28 @@ def get_skymap_filename(graceid):
 
 
 @app.task(shared=False)
-def combine_skymaps(skymap1filebytes, skymap2filebytes):
+def _download_skymaps(se_filename, ext_filename, se_id, ext_id):
+    """Download both superevent and external sky map to be combined."""
+    se_skymap = gracedb.download(se_filename, se_id)
+    ext_skymap = gracedb.download(ext_filename, ext_id)
+    return se_skymap, ext_skymap
+
+
+@app.task(shared=False)
+def combine_skymaps(skymapfilesbytes):
     """This task combines the two input skymaps, in this case the external
     trigger skymap and the LVC skymap and writes to a temporary output file. It
     then returns the contents of the file as a byte array.
     """
+    skymap1filebytes, skymap2filebytes = skymapfilebytes
     with NamedTemporaryFile(mode='rb', suffix='.fits.gz') as combinedskymap, \
             NamedTemporaryFile(content=skymap1filebytes) as skymap1file, \
             NamedTemporaryFile(content=skymap2filebytes) as skymap2file, \
             handling_system_exit():
-        ligo_skymap_combine.main([skymap1file.name,
-                                  skymap2file.name, combinedskymap.name])
+        sky1 = HealpixMap.read_map(skymap1file.name, density=True)
+        sky2 = HealpixMap.read_map(skymap2file.name, density=False)
+        comb_sky = sky1 * sky2
+        comb_sky.write_map(combinedskymap.name)
         return combinedskymap.read()