GaiaDBInterface/views.py

111 lines
3.3 KiB
Python

from rest_framework.views import APIView
#from rest_framework.generics import GenericAPIView
from rest_framework.response import Response
from rest_framework import status
from .models import GaiaSource
from .serializers import GaiaSourceSerializer
from drf_spectacular.utils import extend_schema, OpenApiResponse, OpenApiParameter
import numpy as np
import healpy as hp
from astropy.coordinates import SkyCoord
from astropy import units as u
class ConeSearchView(APIView):
serializer_class = GaiaSourceSerializer
@extend_schema(
description = "GAIA DR3 cone search using healpix indexation. ra, dec, radius in decimal degrees.",
summary = "GAIA DR3 cone search.",
responses = {
200: OpenApiResponse(response=GaiaSourceSerializer(many=True), description="Successful Response"),
400: OpenApiResponse(description="Bad Request"),
404: OpenApiResponse(description="Not Found")
},
# parameters=[
# OpenApiParameter(
# name='ra', description='Right Ascension in decimal degrees', required=True, type=float
# ),
# OpenApiParameter(
# name='dec', description='Declination in decimal degrees', required=True, type=float
# ),
# OpenApiParameter(
# name='radius', description='Search radius in decimal degrees', required=True, type=float
# )
# ],
tags=["GAIA"],
)
def get(self, request): # ra, dec, radius):
try:
ra = float(request.query_params.get('ra'))
dec = float(request.query_params.get('dec'))
radius = float(request.query_params.get('radius'))
except (TypeError, ValueError):
return Response({"error": "Invalid parameters"}, status=status.HTTP_400_BAD_REQUEST)
# radius = float(radius)
# ra = float(ra)
# dec = float(dec)
nside = 2048
#create skycoord for the center of search
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)
#fetch all objects from those healpixes
objects = GaiaSource.objects.filter(healpix_ring_index__in=healpix_indices)
results = [] #initialize the results list
for obj in objects:
source_coordinates = SkyCoord(
ra=obj.ra*u.deg,
dec=obj.dec*u.deg,
frame='icrs'
)
separation = center.separation(source_coordinates)
if separation.degree <= radius:
results.append(obj)
serializer = GaiaSourceSerializer(results, many=True)
return Response(serializer.data, status=status.HTTP_200_OK)
@staticmethod
def get_healpix_indices(ra, dec, radius, nside):
# 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