Fix Bug #158

Test for gamma of 1+0j

NanoVNASaver/RFTools.py

@@ -82,7 +82,10 @@ def reflection_coefficient(z: complex, ref_impedance: float = 50) -> complex:
 
 def gamma_to_impedance(gamma: complex, ref_impedance: float = 50) -> complex:
     """Calculate impedance from gamma"""
-    return ((-gamma - 1) / (gamma - 1)) * ref_impedance
+    try:
+        return ((-gamma - 1) / (gamma - 1)) * ref_impedance
+    except ZeroDivisionError:
+        return math.inf
 
 
 def parseFrequency(freq: str) -> int:
@@ -114,7 +117,6 @@ class Datapoint(NamedTuple):
             return 20 * math.log10(mag)
         return -math.inf
 
-
     @property
     def vswr(self) -> float:
         mag = abs(self.z)

test/test_rftools.py

@@ -64,6 +64,7 @@ class TestRFTools(unittest.TestCase):
     def test_gamma_to_impedance(self):
         self.assertEqual(gamma_to_impedance(0), 50)
         self.assertAlmostEqual(gamma_to_impedance(0.2), 75)
+        self.assertEqual(gamma_to_impedance(1), math.inf)
         # TODO: insert more test values here
 
     def test_clamp_value(self):