From fbdf325b514fa32a52aa364da800b61b86199dac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Holger=20M=C3=BCller?= <zarath@gmx.de>
Date: Sun, 28 Jun 2020 16:57:52 +0200
Subject: [PATCH] Test for cor_att_data function

---
 NanoVNASaver/RFTools.py | 113 ++++++++++++++++++++--------------------
 test/test_rftools.py    |  15 +++++-
 2 files changed, 70 insertions(+), 58 deletions(-)

diff --git a/NanoVNASaver/RFTools.py b/NanoVNASaver/RFTools.py
index e23e8a5..d84049e 100644
--- a/NanoVNASaver/RFTools.py
+++ b/NanoVNASaver/RFTools.py
@@ -26,19 +26,49 @@ FMT_SHORT = Format(max_nr_digits=4)
 FMT_SWEEP = Format(max_nr_digits=9, allow_strip=True)
 
 
-def corr_att_data(data: List[Datapoint], att: float):
-    """Correct the ratio for a given attenuation on s21 input"""
-    if att <= 0:
-        return data
-    else:
-        att = 10**(att/20)
-    ndata = []
-    for dp in data:
-        freq, re, im = dp
-        orig = complex(re, im)
-        corrected = orig * att
-        ndata.append(Datapoint(freq, corrected.real, corrected.imag))
-    return ndata
+class Datapoint(NamedTuple):
+    freq: int
+    re: float
+    im: float
+
+    @property
+    def z(self) -> complex:
+        """ return the datapoint impedance as complex number """
+        return complex(self.re, self.im)
+
+    @property
+    def phase(self) -> float:
+        """ return the datapoint's phase value """
+        return cmath.phase(self.z)
+
+    @property
+    def gain(self) -> float:
+        mag = abs(self.z)
+        if mag > 0:
+            return 20 * math.log10(mag)
+        return -math.inf
+
+    @property
+    def vswr(self) -> float:
+        mag = abs(self.z)
+        if mag == 1:
+            return 1
+        return (1 + mag) / (1 - mag)
+
+    def impedance(self, ref_impedance: float = 50) -> complex:
+        return gamma_to_impedance(self.z, ref_impedance)
+
+    def qFactor(self, ref_impedance: float = 50) -> float:
+        imp = self.impedance(ref_impedance)
+        if imp.real == 0.0:
+            return -1
+        return abs(imp.imag / imp.real)
+
+    def capacitiveEquivalent(self, ref_impedance: float = 50) -> float:
+        return impedance_to_capacitance(self.impedance(ref_impedance), self.freq)
+
+    def inductiveEquivalent(self, ref_impedance: float = 50) -> float:
+        return impedance_to_inductance(self.impedance(ref_impedance), self.freq)
 
 
 def gamma_to_impedance(gamma: complex, ref_impedance: float = 50) -> complex:
@@ -119,47 +149,16 @@ def serial_to_parallel(z: complex) -> complex:
     return complex(z_sq_sum / z.real, z_sq_sum / z.imag)
 
 
-class Datapoint(NamedTuple):
-    freq: int
-    re: float
-    im: float
-
-    @property
-    def z(self) -> complex:
-        """ return the datapoint impedance as complex number """
-        return complex(self.re, self.im)
-
-    @property
-    def phase(self) -> float:
-        """ return the datapoint's phase value """
-        return cmath.phase(self.z)
-
-    @property
-    def gain(self) -> float:
-        mag = abs(self.z)
-        if mag > 0:
-            return 20 * math.log10(mag)
-        return -math.inf
-
-    @property
-    def vswr(self) -> float:
-        mag = abs(self.z)
-        if mag == 1:
-            return 1
-        return (1 + mag) / (1 - mag)
-
-    def impedance(self, ref_impedance: float = 50) -> complex:
-        return gamma_to_impedance(self.z, ref_impedance)
-
-    def qFactor(self, ref_impedance: float = 50) -> float:
-        imp = self.impedance(ref_impedance)
-        if imp.real == 0.0:
-            return -1
-        return abs(imp.imag / imp.real)
-
-    def capacitiveEquivalent(self, ref_impedance: float = 50) -> float:
-        return impedance_to_capacitance(self.impedance(ref_impedance), self.freq)
-
-    def inductiveEquivalent(self, ref_impedance: float = 50) -> float:
-        return impedance_to_inductance(self.impedance(ref_impedance), self.freq)
-
+def corr_att_data(data: List[Datapoint], att: float):
+    """Correct the ratio for a given attenuation on s21 input"""
+    if att <= 0:
+        return data
+    else:
+        att = 10**(att/20)
+    ndata = []
+    for dp in data:
+        freq, re, im = dp
+        orig = complex(re, im)
+        corrected = orig * att
+        ndata.append(Datapoint(freq, corrected.real, corrected.imag))
+    return ndata
diff --git a/test/test_rftools.py b/test/test_rftools.py
index 7fc243a..22bca08 100644
--- a/test/test_rftools.py
+++ b/test/test_rftools.py
@@ -24,7 +24,7 @@ from NanoVNASaver.RFTools import Datapoint, \
     reflection_coefficient, gamma_to_impedance, clamp_value, \
     parallel_to_serial, serial_to_parallel, \
     impedance_to_capacitance, impedance_to_inductance, \
-    groupDelay
+    groupDelay, corr_att_data
 import math
 
 
@@ -121,6 +121,19 @@ class TestRFTools(unittest.TestCase):
         self.assertAlmostEqual(groupDelay(dpoints, 1), -9.514e-5)
         self.assertEqual(groupDelay(dpoints0, 1), 0.0)
 
+    def test_cor_att_data(self):
+        dp1 = [
+            Datapoint(100000, 0.1091, 0.3118),
+            Datapoint(100001, 0.1091, 0.3124),
+            Datapoint(100002, 0.1091, 0.3130),
+        ]
+        dp2 = corr_att_data(dp1, 10)
+        self.assertEqual(dp2[0].gain - dp1[0].gain, 10)
+        self.assertEqual(len(dp1), len(dp2))
+        # ignore negative attenuation
+        dp3 = corr_att_data(dp1, -10)
+        self.assertEqual(dp1, dp3)
+
 
 class TestRFToolsDatapoint(unittest.TestCase):