added healpix order argument to the cone search api

views.py

@@ -9,7 +9,8 @@ from .serializers import GaiaSourceSerializer
 from drf_spectacular.utils import extend_schema, OpenApiResponse, OpenApiParameter
 
 import numpy as np
-import healpy as hp
+# import healpy as hp                        #maybe move to astropy-healpix cone_search_skycoord
+from astropy_healpix import HEALPix
 from astropy.coordinates import SkyCoord
 from astropy import units as u
 
@@ -55,6 +56,7 @@ class ConeSearchView(APIView):
             ra = float(request.query_params.get('ra'))
             dec = float(request.query_params.get('dec'))
             radius = float(request.query_params.get('radius'))
+            order = str(request.query_params.get('order'))
         except (TypeError, ValueError):
             return Response({"error": "Invalid parameters"}, status=status.HTTP_400_BAD_REQUEST)
         # radius = float(radius)
@@ -66,9 +68,12 @@ class ConeSearchView(APIView):
         center = SkyCoord(ra=ra*u.deg, dec=dec*u.deg, frame='icrs')
 
         #fetch healpix indices in the specified disc
-        healpix_indices = self.get_healpix_indices(ra, dec, radius, nside)
+        healpix_indices = self.get_healpix_indices(ra, dec, radius, nside, order)
         #fetch all objects from those healpixes
-        objects = GaiaSource.objects.filter(healpix_ring_index__in=healpix_indices)
+        if order == 'ring':
+            objects = GaiaSource.objects.filter(healpix_ring_index__in=healpix_indices)
+        elif order == 'nested':
+            objects = GaiaSource.objects.filter(healpix_nested_index__in=healpix_indices)
 
         results = [] #initialize the results list
 
@@ -93,18 +98,14 @@ class ConeSearchView(APIView):
     
 
     @staticmethod
-    def get_healpix_indices(ra, dec, radius, nside):
+    def get_healpix_indices(ra, dec, radius, nside, order):
+
+        # Create HEALPix object
+        healpix = HEALPix(nside=nside, order=order, frame='icrs')
 
         # Convert the input coordinates to a SkyCoord object
         center = SkyCoord(ra=ra*u.deg, dec=dec*u.deg, frame='icrs')
 
-        # Convert the center coordinates to HEALPix vector
-        vec = hp.ang2vec(center.ra.deg, center.dec.deg, lonlat=True) 
-
         # Find the pixels within the given radius
-        indices = hp.query_disc(nside, vec, np.radians(radius))        
-        return indices
-
-    
-
-
+        indices = healpix.cone_search_skycoord(center, radius*u.deg)
+        return indices