Covered a new test case for freq channel chopping

meerpipe/archive_utils.py

@@ -148,15 +148,21 @@ def chopping_utility(
 
     # cloning archive and ensuring it has not been dedispersed
     cleaned_ar = ps.Archive_load(archive_path)
+    cleaned_nchan = cleaned_ar.get_nchan()
     chopped_ar = cleaned_ar.clone()
     is_dedispered = chopped_ar.get_dedispersed()
     if is_dedispered:
         chopped_ar.dededisperse()
 
     # Work out highest and lowest frequency channels to cut outside of based on band
     if band == "LBAND":
-        low_freq = 895.92
-        high_freq = 1671.87
+        if cleaned_nchan == 4096:
+            # The 4096 nchan obs have a different zap range
+            low_freq = 895.95
+            high_freq = 1671.7
+        else:
+            low_freq = 895.7
+            high_freq = 1671.46
     elif band == "UHF":
         low_freq = 569.4
         high_freq = 1062.4
@@ -176,6 +182,13 @@ def chopping_utility(
         low_freq = 2665.2
         high_freq = 3458.9
 
+    freqs = chopped_ar.get_frequencies()
+    nchan_remove = ( cleaned_nchan * 3 ) // 64
+    print(nchan_remove)
+    logger.debug(f"{band} below zap {freqs[nchan_remove-1]}-{freqs[nchan_remove]} and above zap {freqs[-nchan_remove-1]}-{freqs[-nchan_remove]}")
+    count_below_threshold = len([value for value in freqs if value < low_freq])
+    count_above_threshold = len([value for value in freqs if value > high_freq])
+    logger.debug(f"{band} {count_below_threshold} below zap and {count_above_threshold} above zap")
 
     # complex structure required as with every channel removal, indexes of chopped_ar get reset
     recheck = True
@@ -197,6 +210,7 @@ def chopping_utility(
         assert chopped_ar.get_nchan() == 928
     else:
         # A simple check to ensure channels are a factor of 32
+        print(chopped_ar.get_nchan())
         assert chopped_ar.get_nchan() % 32 == 0
 
     logger.info("Done extracting")

tests/test_archive_utils.py

@@ -28,6 +28,7 @@ def test_chopping_utility():
         ("LBAND", "J2317+1439_2022-12-03-15:09:15_zap.ar", 4096, 3712),
         ("UHF", "J1350-5115_2022-01-03-04:04:15_zap.ar", 4096, 3712),
         ("SBAND_0", "J0737-3039A_2023-05-16-11:38:55_zap_ch16384.ar", 16384, 14848),
+        ("LBAND", "J0737-3039A_2022-09-18-07:10:50_zap.ar", 16384, 14848),
     ]
     for band, archive, input_nchan, output_nchan in test_archives:
         logger.info(f"Testing chopping utility for {archive} in {band} band")
@@ -41,6 +42,7 @@ def test_chopping_utility():
         # Check the nchan of the chopped archive
         chopped_archive = archive.replace(".ar", "_chopped.ar")
         ar = ps.Archive_load(os.path.join(TEST_DATA_DIR, chopped_archive))
+        logger.info(f"Testing {ar.get_nchan()} == {output_nchan}")
         assert ar.get_nchan() == output_nchan
 
         # Remove the chopped archive