SW-43: minor fixes in the beamlet searching

CAL/CalibrationCommon/lib/datacontainers/holography_dataset.py

@@ -84,6 +84,8 @@ class HolographyDataset():
         # a dict of dicts and eventually str, ndarray or that can be converted in a ndarray calling
         # numpy.array()
         self.derived_data = None
+        # the index of the central beamlet
+        self.central_beamlet = None
 
     @staticmethod
     def compare_dicts(dict1, dict2):
@@ -179,7 +181,9 @@ class HolographyDataset():
             # and iterate over the beamlets.
             for beamlet in beamlets:
                 beamlet_string = str(beamlet)
-                (ra, dec, epoch) = ra_dec[frequency_string][beamlet_string]
+                ra = ra_dec[frequency_string][beamlet_string]['RA']
+                dec = ra_dec[frequency_string][beamlet_string]['DEC']
+
                 # calculate a pseudo distance that is an indicator if this
                 # beamlet is closer to the source than the ones before.
                 # Note that I am too lazy to calculate the spherical distance.
@@ -187,7 +191,7 @@ class HolographyDataset():
                 # the geometrical distance are not really cutting it since RA
                 # and DEC are coordinates of a spherical coordinate system.
                 # But here the pseudo distance is good enough. 
-                pseudo_distance[frequency][beamlet] = math.abs(ra - source_ra) + math.abs(dec - source_dec)
+                pseudo_distance[frequency_string][beamlet_string] = abs(ra - source_ra) + abs(dec - source_dec)
 
         # OK.  Done with all the iteration business.  Now check if across all
         # frequencies the same beamlet is the central one.  It is allowed that
@@ -220,7 +224,7 @@ class HolographyDataset():
             logger.debug("All is good, unicorns everywhere, there is only one central beamlet \"%s\" for all frequencies.", self.central_beamlet)
         else:
             logger.warn("Multiple central beamlets have been identified: ", central_beamlet)
-        return central_beamlet
+        return list(central_beamlet)
 
     def load_from_beam_specification_and_ms(self, station_name, list_of_hbs_ms_tuples):
         """
@@ -231,10 +235,14 @@ class HolographyDataset():
 
         """
         logger.info("Creating a holography data set for station \"%s\"...", station_name)
-        self.__collect_preliminary_information(station_name, list_of_hbs_ms_tuples)
-        self.__read_data(station_name, list_of_hbs_ms_tuples)
-        self.central_beamlets = self.find_central_beamlets(self.source_position, self.ra_dec, self.frequencies, self.beamlets)
-        logger.info("Creation of a holography data set for station \"%s\" done.", station_name)
+        try:
+            self.__collect_preliminary_information(station_name, list_of_hbs_ms_tuples)
+            self.__read_data(station_name, list_of_hbs_ms_tuples)
+            self.central_beamlets = self.find_central_beamlets(self.source_position, self.ra_dec, self.frequencies, self.beamlets)
+            logger.info("Creation of a holography data set for station \"%s\" done.", station_name)
+        except Exception as e:
+            logger.exception("Errore creating dataset for station \"%s\": %s", station_name, e)
+            raise e
 
     def __read_data(self, station_name, list_of_hbs_ms_tuples):
         """