Fix a bug with beam freq selects using freq buffers

CHANGELOG.md

@@ -14,6 +14,10 @@ string/object mode switch.
 - Setting the `select.bls` property in the obsparams file now selects baselines _before_
 creating the UVData object, rather than down-selecting afterwards, saving memory and time.
 
+### Fixed
+- A bug when specifying a frequency buffer for beam frequency selects in telescope
+config files.
+
 ## [1.3.1] - 2024-07-18
 
 ### Added

src/pyuvsim/data/test_config/28m_triangle_10time_10chan_freqbuff.yaml

@@ -0,0 +1,16 @@
+beam_paths:
+  0: !UVBeam
+    filename: HERA_NicCST.beamfits
+    path_variable: pyuvsim.data.DATA_PATH
+  1: !AnalyticBeam
+    class: UniformBeam
+  2: !AnalyticBeam
+    class: GaussianBeam
+    sigma: 0.02
+  3: !AnalyticBeam
+    class: AiryBeam
+    diameter: 14.6
+telescope_location: (-30.721527777777847, 21.428305555555557, 1073.0000000046566)
+telescope_name: Triangle
+select:
+  freq_buffer: 1000000.0  # Restrict beam to read frequencies within 1MHz of sim freqs.

src/pyuvsim/data/test_config/obsparam_diffuse_sky_freqbuf_tel.yaml

@@ -0,0 +1,23 @@
+filing:
+  outdir: '.'
+  outfile_name: 'sim_results.uvfits'
+freq:
+  Nfreqs: 1
+  bandwidth: 800000.0
+  start_freq: 100000000.0
+sources:
+  catalog: 'mock'
+  time: 2457458.1738949567
+  mock_arrangement: 'diffuse'
+  diffuse_model: 'monopole'
+  map_nside: 128
+telescope:
+  telescope_config_name: '28m_triangle_10time_10chan_freqbuff.yaml'
+  array_layout: 'triangle_bl_layout.csv'
+time:
+  Ntimes: 1
+  integration_time: 11.0
+  start_time: 2457458.1738949567
+ordering:
+  conjugation_convention: ant1<ant2
+  blt_order: [time, baseline]

src/pyuvsim/simsetup.py

@@ -1109,17 +1109,18 @@ def _construct_beam_list(
         )
 
     select = telconfig.pop("select", {})
+    freq_buffer = select.pop("freq_buffer", None)
     if (
         freq_range is not None
         and "freq_range" not in select
-        and "freq_buffer" not in select
+        and freq_buffer is None
     ):
         select["freq_range"] = freq_range
-    if "freq_buffer" in select and "freq_range" not in select:
-        freq_arr_val = freq_array.to("Hz").value
+    if freq_buffer is not None and "freq_range" not in select:
+        freq_arr_val = freq_array
         freq_range = (
-            freq_arr_val.min() - select["freq_buffer"],
-            freq_arr_val.max() + select["freq_buffer"],
+            freq_arr_val.min() - freq_buffer,
+            freq_arr_val.max() + freq_buffer,
         )
         select["freq_range"] = freq_range
 

tests/test_simsetup.py

@@ -1831,7 +1831,7 @@ def test_beamlist_init_freqrange(sel_type):
     }
 
     Nfreqs = 10
-    freqs = np.linspace(120, 145, Nfreqs) * 1e6 * units.Hz
+    freqs = np.linspace(120, 145, Nfreqs) * 1e6
 
     freq_range = [117e6, 148e6]
     if sel_type == "freq_range":
@@ -2057,7 +2057,7 @@ def test_skymodeldata_attr_bases(inds, cat_with_some_pols):
     assert smd_copy.stokes_I.base is smd.stokes_I.base
 
 
-def test_simsetup_with_freq_buffer():
+def test_simsetup_with_obsparam_freq_buffer():
     fl = os.path.join(SIM_DATA_PATH, "test_config", "obsparam_diffuse_sky_freqbuf.yaml")
 
     with check_warnings(
@@ -2069,3 +2069,11 @@ def test_simsetup_with_freq_buffer():
         _, beams, _ = simsetup.initialize_uvdata_from_params(fl, return_beams=True)
 
     assert beams[0].beam.freq_array.max() < 101e6
+
+
+def test_simsetup_with_freq_buffer():
+    fl = os.path.join(SIM_DATA_PATH, "test_config", "obsparam_diffuse_sky_freqbuf_tel.yaml")
+
+    _, beams, _ = simsetup.initialize_uvdata_from_params(fl, return_beams=True)
+
+    assert beams[0].beam.freq_array.max() < 101e6