diff --git a/src/openqlab/analysis/__init__.py b/src/openqlab/analysis/__init__.py
index bc6d9d728a15090391efa43c2bc2e00023010245..80354e0181edd48412e3e33e750a475f6371463f 100644
--- a/src/openqlab/analysis/__init__.py
+++ b/src/openqlab/analysis/__init__.py
@@ -1,4 +1,4 @@
 from .servo_design import ServoDesign
 from .gaussian_beam import fit_beam_data, GaussianBeam
 from ..conversion import db
-from . import phase
+from . import phase, cavity
diff --git a/src/openqlab/plots/time_domain.py b/src/openqlab/plots/time_domain.py
index 92cc615de97b1cf6d316e1d9e69b7e06f599e48f..0c604b4f2737680d87f8dad28f020e0b2d322d0e 100644
--- a/src/openqlab/plots/time_domain.py
+++ b/src/openqlab/plots/time_domain.py
@@ -80,8 +80,8 @@ def scope(traces, title='Oscilloscope View'):
     from mpl_toolkits.axes_grid1 import host_subplot
     import mpl_toolkits.axisartist as AA
 
-    traces = DataContainer(
-        traces)  # then you can also conviniently put in a single column, which would otherwise be a series
+    # then you can also conviniently put in a single column, which would otherwise be a series
+    traces = DataContainer(traces)
     offset = 50
     Ntraces = len(traces.columns)
     if Ntraces > 4:
@@ -91,7 +91,7 @@ def scope(traces, title='Oscilloscope View'):
     host = host_subplot(111, axes_class=AA.Axes)
     plt.subplots_adjust(right=1.0 - 0.11 * (Ntraces - 1))
 
-    line, = host.plot(traces.index, traces.iloc[:, 0], label=traces.columns[0])
+    line, = host.plot(np.array(traces.index), np.array(traces.iloc[:, 0]), label=traces.columns[0])
     host.set_ylabel(traces.columns[0])
     host.set_xlabel(traces.index.name)
     host.axis['left'].label.set_color(line.get_color())
@@ -111,7 +111,7 @@ def scope(traces, title='Oscilloscope View'):
             pax.major_ticks.set_ticksize(4.0)
             ax.axis['right'] = pax
 
-        line, = ax.plot(traces.index, traces.iloc[:, ii], label=traces.columns[ii])
+        line, = ax.plot(np.array(traces.index), np.array(traces.iloc[:, ii]), label=traces.columns[ii])
         ax.axis['right'].toggle(all=True)
         ax.set_ylabel(traces.columns[ii])
         ax.axis['right'].label.set_color(line.get_color())
diff --git a/src/tests/test_plots.py b/src/tests/test_plots.py
index 20bee8302bd8cc71917c192da92a1dee626e95c7..7ef36e3bf92abe5fb87bd64770de8f2a75a88a0c 100644
--- a/src/tests/test_plots.py
+++ b/src/tests/test_plots.py
@@ -51,3 +51,14 @@ class TestAmplitudePhase(unittest.TestCase):
     def test_clamp_phase_warns(self):
         with self.assertWarns(DeprecationWarning):
             plots.frequency_domain._clamp_phase(4)
+
+
+class TestTimeDomain(unittest.TestCase):
+    def setUp(self):
+        self.data = io.read(
+                r'./ContainerTestData/SuccedingImport/Oscilloscope/Keysight/20180606_001.csv')
+
+    def test_default_plot(self):
+        fig = plots.scope(self.data)
+        fig = plots.scope(self.data.iloc[:, 0])
+        self.assertIsInstance(fig, matplotlib.figure.Figure)