L2DTS-272: Test transpose of XST data

tests/statistics/test_collector.py

@@ -135,17 +135,19 @@ class TestXSTCollector(base.TestCase):
                         f"but was written to the XST matrix.",
                     )
 
-    def test_conjugated_packet(self):
-        """Test packet payload conjugation with a baseline (a,b) where a<b"""
+    def test_conjugated_transposed_packet(self):
+        """Test packet payload conjugation & transposewith a baseline (a,b) where a<b"""
 
         collector = XSTCollector()
 
-        # a valid packet as obtained from SDP, with 64-bit BE 1+1j as payload, at
-        # baseline (0,12)                                                VV  VV
+        # a valid packet as obtained from SDP.
+        # the first 72 samples are 1+1j, the second 72 samples are 2+2j (64-bit BE).
+        # at baseline (0,12)                                                 VV  VV
         packet = (
             b"X\x05\x00\x00\x00\x00\x00\x00\x10\x08\x00\x02\xfa\xef\x00f\x00\x0c\x0c"
             b"\x08\x01 \x14\x00\x00\x01!\xd9&z\x1b\xb3"
-            + 288 * b"\x00\x00\x00\x00\x00\x00\x00\x01"
+            + 144 * b"\x00\x00\x00\x00\x00\x00\x00\x01"
+            + 144 * b"\x00\x00\x00\x00\x00\x00\x00\x02"
         )
 
         # parse it ourselves to extract info nicely
@@ -165,6 +167,11 @@ class TestXSTCollector(base.TestCase):
         # zero
         xst_values = collector.xst_values()[0]
 
+        # number of complex values that should end up in the XST matrix
+        correct_nr_values = 144
+        # number of values we've counted so far
+        actual_nr_values = 0
+
         for baseline_a in range(collector.MAX_INPUTS):
             for baseline_b in range(collector.MAX_INPUTS):
                 if baseline_b > baseline_a:
@@ -184,12 +191,25 @@ class TestXSTCollector(base.TestCase):
                 )
 
                 if baseline_a_was_in_packet and baseline_b_was_in_packet:
+                    # through conjugation, the imaginary part is made negative
+                    # through transposition, the second dimension (b) now is the divider
+                    # between the two distinct values
+                    if baseline_b - fields.first_baseline[0] < 6:
                         self.assertEqual(
                             1 - 1j,
                             xst_values[baseline_a][baseline_b],
                             msg=f"element [{baseline_a}][{baseline_b}] did not end up "
-                        f"conjugated in XST matrix.",
+                            f"conjugated & transposed in XST matrix.",
                         )
+                    else:
+                        self.assertEqual(
+                            2 - 2j,
+                            xst_values[baseline_a][baseline_b],
+                            msg=f"element [{baseline_a}][{baseline_b}] did not end up "
+                            f"conjugated & transposed in XST matrix.",
+                        )
+
+                    actual_nr_values += 1
                 else:
                     self.assertEqual(
                         0 + 0j,
@@ -198,6 +218,8 @@ class TestXSTCollector(base.TestCase):
                         f"but was written to the XST matrix.",
                     )
 
+        self.assertEqual(correct_nr_values, actual_nr_values, "Mismatch between number of values in the packet and in the resulting matrix")
+
     def test_multiple_subbands(self):
         collector = XSTCollector()