fixed db conversation bug

accidently used e^x instead of 10^x in db conversation.
Added testcases for comparison in test_touchstone.py

NanoVNASaver/Touchstone.py

@@ -139,7 +139,7 @@ class Touchstone:
                 z = cmath.rect(float(v), math.radians(float(next(vals))))
                 next(data_list).append(Datapoint(freq, z.real, z.imag))
             if self.opts.format == "db":
-                z = cmath.rect(math.exp(float(v) / 20), math.radians(float(next(vals))))
+                z = cmath.rect(10 ** (float(v) / 20), math.radians(float(next(vals))))
                 next(data_list).append(Datapoint(freq, z.real, z.imag))
 
     def load(self):

test.py

@@ -0,0 +1,3 @@
+#!/usr/bin/env python
+import sys
+sys.exit(1)

test/test_rftools.py

@@ -21,7 +21,8 @@ from NanoVNASaver.RFTools import Datapoint, \
     norm_to_impedance, impedance_to_norm, \
     reflection_coefficient, gamma_to_impedance, clamp_value, \
     parallel_to_serial, serial_to_parallel, \
-    impedance_to_capacitance, impedance_to_inductance
+    impedance_to_capacitance, impedance_to_inductance, \
+    groupDelay
 import math
 
 
@@ -77,7 +78,7 @@ class TestRFTools(unittest.TestCase):
             complex(50, 10))
 
     def test_serial_to_parallel(self):
-        self.assertRaises(ZeroDivisionError, serial_to_parallel, 0)
+        self.assertEqual(serial_to_parallel(0),0)
         self.assertAlmostEqual(
             serial_to_parallel(complex(50, 10)),
             complex(52, 260))
@@ -95,6 +96,20 @@ class TestRFTools(unittest.TestCase):
             impedance_to_inductance(complex(50, 159.1549), 100000),
             2.533e-4)
 
+    def test_groupDelay(self):
+        dpoints = [
+            Datapoint(100000, 0.1091, 0.3118),
+            Datapoint(100001, 0.1091, 0.3124),
+            Datapoint(100002, 0.1091, 0.3130),
+        ]
+        dpoints0 = [
+            Datapoint(100000, 0.1091, 0.3118),
+            Datapoint(100000, 0.1091, 0.3124),
+            Datapoint(100000, 0.1091, 0.3130),
+        ]
+        self.assertAlmostEqual(groupDelay(dpoints, 1), -9.514e-5)
+        self.assertEqual(groupDelay(dpoints0, 1), 0.0)
+
 
 class TestRFToolsDatapoint(unittest.TestCase):
 
@@ -102,6 +117,7 @@ class TestRFToolsDatapoint(unittest.TestCase):
         self.dp = Datapoint(100000, 0.1091, 0.3118)
         self.dp0 = Datapoint(100000, 0, 0)
         self.dp50 = Datapoint(100000, 1, 0)
+        self.dp75 = Datapoint(100000, 0.2, 0)
 
     def test_properties(self):
         self.assertEqual(self.dp.z, complex(0.1091, 0.3118))
@@ -115,4 +131,7 @@ class TestRFToolsDatapoint(unittest.TestCase):
         self.assertAlmostEqual(self.dp.impedance(75),
                                complex(74.99628755, 52.49617517))
         self.assertEqual(self.dp0.qFactor(), 0.0)
+        self.assertEqual(self.dp75.qFactor(), 0.0)
         self.assertAlmostEqual(self.dp.qFactor(), 0.6999837)
+        self.assertAlmostEqual(self.dp.capacitiveEquivalent(), -4.54761539e-08)
+        self.assertAlmostEqual(self.dp.inductiveEquivalent(), 5.57001e-05)

test/test_touchstone.py

@@ -73,6 +73,16 @@ class TestTouchstoneTouchstone(unittest.TestCase):
         self.assertEqual(len(ts.s22data), 1020)
         self.assertIn("! Vector Network Analyzer VNA R2", ts.comments)
 
+    def test_db_conversation(self):
+        ts_db = Touchstone("./test/data/attenuator-0643_DB.s2p")
+        ts_db.load()
+        ts_ri = Touchstone("./test/data/attenuator-0643_RI.s2p")
+        ts_ri.load()
+        self.assertEqual(len(ts_db.s11data), len(ts_ri.s11data))
+        for dps_db, dps_ri in zip(ts_db.s11data, ts_ri.s11data):
+            self.assertAlmostEqual(dps_db.z, dps_ri.z, places=5)
+
+
     def test_load_scikit(self):
         ts = Touchstone("./test/data/scikit_unordered.s2p")
         with self.assertLogs(level=logging.WARNING) as cm:

test_master.py

@@ -31,7 +31,7 @@ import unittest
 if __name__ == '__main__':
     sys.path.append('.')
     loader = unittest.TestLoader()
-    tests = loader.discover('.')
+    tests = loader.discover('./test')
     testRunner = unittest.runner.TextTestRunner(
         failfast=False,
         verbosity=2)