diff --git a/NanoVNASaver/Chart.py b/NanoVNASaver/Chart.py
index 0e45b5a..34213bf 100644
--- a/NanoVNASaver/Chart.py
+++ b/NanoVNASaver/Chart.py
@@ -1057,13 +1057,8 @@ class LogMagChart(FrequencyChart):
 
     @staticmethod
     def logMag(p: Datapoint) -> float:
-        re = p.re
-        im = p.im
-        re50 = 50 * (1 - re * re - im * im) / (1 + re * re + im * im - 2 * re)
-        im50 = 50 * (2 * im) / (1 + re * re + im * im - 2 * re)
-        # Calculate the reflection coefficient
-        mag = math.sqrt((re50 - 50) * (re50 - 50) + im50 * im50) / math.sqrt((re50 + 50) * (re50 + 50) + im50 * im50)
-        return -20 * math.log10(mag)
+        from NanoVNASaver.NanoVNASaver import  NanoVNASaver
+        return NanoVNASaver.gain(p)
 
 
 class QualityFactorChart(FrequencyChart):
diff --git a/NanoVNASaver/Marker.py b/NanoVNASaver/Marker.py
index 68d1dc2..9697fe6 100644
--- a/NanoVNASaver/Marker.py
+++ b/NanoVNASaver/Marker.py
@@ -85,7 +85,6 @@ class Marker(QtCore.QObject):
 
         line = QtWidgets.QFrame()
         line.setFrameShape(QtWidgets.QFrame.VLine)
-        #line.setFrameShadow(QtWidgets.QFrame.Sunken)
 
         left_form = QtWidgets.QFormLayout()
         right_form = QtWidgets.QFormLayout()
@@ -169,12 +168,24 @@ class Marker(QtCore.QObject):
         from NanoVNASaver.NanoVNASaver import NanoVNASaver
         if self.location != -1:
             im50, re50, vswr = NanoVNASaver.vswr(s11data[self.location])
-            rp = (re50 ** 2 + im50 ** 2) / re50
-            xp = (re50 ** 2 + im50 ** 2) / im50
-            re50 = round(re50, 4 - max(0, math.floor(math.log10(abs(re50)))))
-            rp = round(rp, 4 - max(0, math.floor(math.log10(abs(rp)))))
-            im50 = round(im50, 4 - max(0, math.floor(math.log10(abs(im50)))))
-            xp = round(xp, 4 - max(0, math.floor(math.log10(abs(xp)))))
+            if re50 > 0:
+                rp = (re50 ** 2 + im50 ** 2) / re50
+                rp = round(rp, 4 - max(0, math.floor(math.log10(abs(rp)))))
+
+                re50 = round(re50, 4 - max(0, math.floor(math.log10(abs(re50)))))
+            else:
+                rp = 0
+                re50 = 0
+
+            if im50 > 0:
+                xp = (re50 ** 2 + im50 ** 2) / im50
+                xp = round(xp, 4 - max(0, math.floor(math.log10(abs(xp)))))
+            else:
+                xp = 0
+
+            if im50 != 0:
+                im50 = round(im50, 4 - max(0, math.floor(math.log10(abs(im50)))))
+
             if im50 < 0:
                 im50str = " -j" + str(-1 * im50)
             else:
@@ -190,7 +201,6 @@ class Marker(QtCore.QObject):
             self.impedance_label.setText(str(re50) + im50str)
             self.parallel_r_label.setText(str(rp) + " \N{OHM SIGN}")
             self.parallel_x_label.setText(xpstr)
-            #self.returnloss_label.setText(str(round(20 * math.log10((vswr - 1) / (vswr + 1)), 3)) + " dB")
             self.returnloss_label.setText(str(round(NanoVNASaver.gain(s11data[self.location]), 3)) + " dB")
             capacitance = NanoVNASaver.capacitanceEquivalent(im50, s11data[self.location].freq)
             inductance = NanoVNASaver.inductanceEquivalent(im50, s11data[self.location].freq)
@@ -200,7 +210,12 @@ class Marker(QtCore.QObject):
             if vswr < 0:
                 vswr = "-"
             self.vswr_label.setText(str(vswr))
-            self.quality_factor_label.setText(str(round(NanoVNASaver.qualifyFactor(s11data[self.location]), 1)))
+            q = NanoVNASaver.qualifyFactor(s11data[self.location])
+            if q > 10000 or q < 0:
+                q_str = "\N{INFINITY}"
+            else:
+                q_str = str(round(q, 1))
+            self.quality_factor_label.setText(q_str)
             self.s11_phase_label.setText(
                 str(round(PhaseChart.angle(s11data[self.location]), 2)) + "\N{DEGREE SIGN}")
             if len(s21data) == len(s11data):
diff --git a/NanoVNASaver/NanoVNASaver.py b/NanoVNASaver/NanoVNASaver.py
index e85d470..f3a80f0 100644
--- a/NanoVNASaver/NanoVNASaver.py
+++ b/NanoVNASaver/NanoVNASaver.py
@@ -795,10 +795,10 @@ class NanoVNASaver(QtWidgets.QWidget):
     def qualifyFactor(data: Datapoint):
         im50, re50, _ = NanoVNASaver.vswr(data)
         if re50 != 0:
-            Q = im50 / re50
+            Q = abs(im50 / re50)
         else:
-            Q = 0
-        return abs(Q)
+            Q = -1
+        return Q
 
     @staticmethod
     def capacitanceEquivalent(im50, freq) -> str:
@@ -818,7 +818,7 @@ class NanoVNASaver(QtWidgets.QWidget):
     def inductanceEquivalent(im50, freq) -> str:
         if freq == 0:
             return "- nH"
-        inductance = im50 * 1000000000/ (freq * 2 * math.pi)
+        inductance = im50 * 1000000000 / (freq * 2 * math.pi)
         if abs(inductance) > 10000:
             return str(round(inductance / 1000, 2)) + " μH"
         elif abs(inductance) > 1000: