Fixed galactic range coord problem

astropy · Oct 9, 2024 · 1aa9bfd · 1aa9bfd
1 parent 0667ec8
commit 1aa9bfd
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Showing 2 changed files with 25 additions and 20 deletions.
diff --git a/astroquery/alma/tapsql.py b/astroquery/alma/tapsql.py
@@ -69,16 +69,21 @@ def _gen_pos_sql(field, value):
                     dec_min = -90
                 if dec_max is None:
                     dec_max = 90
-                min_pt = coord.SkyCoord(ra_min, dec_min, unit=u.deg,
-                                        frame=frame)
-                max_pt = coord.SkyCoord(ra_max, dec_max, unit=u.deg,
-                                        frame=frame)
-                result += \
-                    "(INTERSECTS(RANGE_S2D({},{},{},{}), s_region) = 1)".\
-                    format(min_pt.icrs.ra.to(u.deg).value,
-                           max_pt.icrs.ra.to(u.deg).value,
-                           min_pt.icrs.dec.to(u.deg).value,
-                           max_pt.icrs.dec.to(u.deg).value)
+                min_pt = coord.SkyCoord(ra_min, dec_min, unit=u.deg)
+                ra_min, dec_min = min_pt.ra.value, min_pt.dec.value
+                max_pt = coord.SkyCoord(ra_max, dec_max, unit=u.deg)
+                ra_max, dec_max = max_pt.ra.value, max_pt.dec.value
+                if frame == 'galactic':
+                    # intersect with s_region is too complicated. ALMA indicated that
+                    # the use of gal_longitude and gal_latitude is good enough
+                    # approximation in this less comon use case
+                    result += ('gal_longitude>={} AND gal_longitude<={} AND '
+                               'gal_latitude>={} and gal_latitude<={}').format(
+                        ra_min, ra_max, dec_min, dec_max)
+                else:
+                    result += \
+                        "(INTERSECTS(RANGE_S2D({},{},{},{}), s_region) = 1)".\
+                        format(ra_min, ra_max, dec_min, dec_max)
             else:
                 raise ValueError('Cannot interpret ra({}), dec({}'.
                                  format(ra, dec))

diff --git a/astroquery/alma/tests/test_alma.py b/astroquery/alma/tests/test_alma.py
@@ -123,18 +123,18 @@ def test_gen_pos_sql():
     assert _gen_sql({'galactic': '1 2, 3'}) == common_select + "(INTERSECTS(" \
         "CIRCLE('ICRS',{},{},3.0), s_region) = 1)".format(
         center.icrs.ra.to(u.deg).value, center.icrs.dec.to(u.deg).value)
-    min_point = coord.SkyCoord('12:13:14.0', '-00:01:02.1', unit=u.deg,
-                               frame='galactic')
-    max_point = coord.SkyCoord('12:14:14.0', '-00:00:02.1', unit=(u.deg, u.deg),
-                               frame='galactic')
+    gal_longitude = ('12:13:14.0', '12:14:14.0')
+    gal_latitude = ('-00:01:02.1', '-00:00:02.1')
+    min_pt = coord.SkyCoord(gal_longitude[0], gal_latitude[0], unit=u.deg)
+    long_min, lat_min = min_pt.ra.value, min_pt.dec.value
+    max_pt = coord.SkyCoord(gal_longitude[1], gal_latitude[1], unit=u.deg)
+    long_max, lat_max = max_pt.ra.value, max_pt.dec.value
     assert _gen_sql(
-        {'galactic': '12:13:14.0..12:14:14.0 -00:01:02.1..-00:00:02.1'}) == \
+        {'galactic': '{}..{} {}..{}'.format(
+            gal_longitude[0], gal_longitude[1], gal_latitude[0], gal_latitude[1])}) == \
         common_select +\
-        "(INTERSECTS(RANGE_S2D({},{},{},{}), s_region) = 1)".format(
-            min_point.icrs.ra.to(u.deg).value,
-            max_point.icrs.ra.to(u.deg).value,
-            min_point.icrs.dec.to(u.deg).value,
-            max_point.icrs.dec.to(u.deg).value)
+        'gal_longitude>={} AND gal_longitude<={} AND gal_latitude>={} and gal_latitude<={}'.format(
+            long_min, long_max, lat_min, lat_max)
 
     # combination of frames
     center = coord.SkyCoord(1, 2, unit=u.deg, frame='galactic')