diff --git a/frc971/analysis/plot.py b/frc971/analysis/plot.py
new file mode 100644
index 0000000..4367c08
--- /dev/null
+++ b/frc971/analysis/plot.py
@@ -0,0 +1,128 @@
+#!/usr/bin/python3
+# Sample usage:
+# bazel run -c opt //frc971/analysis:plot  -- --logfile /tmp/log.fbs --config gyro.pb
+import argparse
+import json
+import os.path
+from pathlib import Path
+import sys
+
+from frc971.analysis.py_log_reader import LogReader
+from frc971.analysis.plot_config_pb2 import PlotConfig, Signal
+from google.protobuf import text_format
+
+import matplotlib
+from matplotlib import pyplot as plt
+
+
+class Plotter:
+    def __init__(self, plot_config: PlotConfig, reader: LogReader):
+        self.config = plot_config
+        self.reader = reader
+        # Data streams, indexed by alias.
+        self.data = {}
+
+    def process_logfile(self):
+        aliases = set()
+        for channel in self.config.channel:
+            if channel.alias in aliases:
+                raise ValueError("Duplicate alias " + channel.alias)
+            aliases.add(channel.alias)
+            if not self.reader.subscribe(channel.name, channel.type):
+                raise ValueError("No such channel with name " + channel.name +
+                                 " and type " + channel.type)
+
+        self.reader.process()
+
+        for channel in self.config.channel:
+            self.data[channel.alias] = []
+            for message in self.reader.get_data_for_channel(
+                    channel.name, channel.type):
+                valid_json = message[2].replace('nan', '"nan"')
+                parsed_json = json.loads(valid_json)
+                self.data[channel.alias].append((message[0], message[1],
+                                                 parsed_json))
+
+    def plot_signal(self, axes: matplotlib.axes.Axes, signal: Signal):
+        if not signal.channel in self.data:
+            raise ValueError("No channel alias " + signal.channel)
+        field_path = signal.field.split('.')
+        monotonic_time = []
+        signal_data = []
+        for entry in self.data[signal.channel]:
+            monotonic_time.append(entry[0] * 1e-9)
+            value = entry[2]
+            for name in field_path:
+                value = value[name]
+            # Catch NaNs and convert them to floats.
+            value = float(value)
+            signal_data.append(value)
+        label_name = signal.channel + "." + signal.field
+        axes.plot(monotonic_time, signal_data, label=label_name)
+
+    def plot(self):
+        for figure_config in self.config.figure:
+            fig = plt.figure()
+            num_subplots = len(figure_config.axes)
+            for ii in range(num_subplots):
+                axes = fig.add_subplot(num_subplots, 1, ii + 1)
+                axes_config = figure_config.axes[ii]
+                for signal in axes_config.signal:
+                    self.plot_signal(axes, signal)
+                axes.legend()
+                axes.set_xlabel("Monotonic Time (sec)")
+                if axes_config.HasField("ylabel"):
+                    axes.set_ylabel(axes_config.ylabel)
+
+
+def main(argv):
+    parser = argparse.ArgumentParser(
+        description="Plot data from an aos logfile.")
+    parser.add_argument(
+        "--logfile",
+        type=str,
+        required=True,
+        help="Path to the logfile to parse.")
+    parser.add_argument(
+        "--config",
+        type=str,
+        required=True,
+        help="Name of the plot config to use.")
+    parser.add_argument(
+        "--config_dir",
+        type=str,
+        default="frc971/analysis/plot_configs",
+        help="Directory to look for plot configs in.")
+    args = parser.parse_args(argv[1:])
+
+    if not os.path.isdir(args.config_dir):
+        print(args.config_dir + " is not a directory.")
+        return 1
+    config_path = os.path.join(args.config_dir, args.config)
+    if not os.path.isfile(config_path):
+        print(config_path +
+              " does not exist or is not a file--available configs are")
+        for file_name in os.listdir(args.config_dir):
+            print(os.path.basename(file_name))
+        return 1
+
+    config = PlotConfig()
+    with open(config_path) as config_file:
+        text_format.Merge(config_file.read(), config)
+
+    if not os.path.isfile(args.logfile):
+        print(args.logfile + " is not a file.")
+        return 1
+
+    reader = LogReader(args.logfile)
+
+    plotter = Plotter(config, reader)
+    plotter.process_logfile()
+    plotter.plot()
+    plt.show()
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))