Merge pull request cantools#252 from erzoe/master

New subcommand plot
Gussy · Jan 4, 2021 · 6ab0eac · 6ab0eac
2 parents 7d97b43 + 0b87191
commit 6ab0eac
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diff --git a/README.rst b/README.rst
@@ -23,6 +23,8 @@ CAN BUS tools in Python 3.
 
 - CAN bus monitor.
 
+- Graphical plots of signals.
+
 Project homepage: https://github.com/eerimoq/cantools
 
 Documentation: https://cantools.readthedocs.io
@@ -119,6 +121,46 @@ Alternatively, the decoded message can be printed on a single line:
      vcan0  1F0   [8]  80 4A 0F 00 00 00 00 00 :: ExampleMessage(Enable: 'Enabled' -, AverageRadius: 0.0 m, Temperature: 255.92 degK)
      vcan0  1F0   [8]  80 4A 0F 00 00 00 00 00 :: ExampleMessage(Enable: 'Enabled' -, AverageRadius: 0.0 m, Temperature: 255.92 degK)
 
+The plot subcommand
+^^^^^^^^^^^^^^^^^^^
+
+The plot subcommand is similar to the decode subcommand but messages are visualized using `matplotlib`_ instead of being printed to stdout.
+
+.. code-block:: bash
+
+    $ cat candump-2021-01-04_180521.log
+    (1609779922.655421) vcan0 00000343#B204B9049C049C04
+    (1609779922.655735) vcan0 0000024A#120527052E051905
+    (1609779923.657524) vcan0 00000343#C404C404CB04C404
+    (1609779923.658086) vcan0 0000024A#8B058B058B059205
+    (1609779924.659912) vcan0 00000343#5C04790479045504
+    (1609779924.660471) vcan0 0000024A#44064B0659064406
+    (1609779925.662277) vcan0 00000343#15040704F203F203
+    (1609779925.662837) vcan0 0000024A#8B069906A706A706
+    (1609779926.664191) vcan0 00000343#BC03B503A703BC03
+    (1609779926.664751) vcan0 0000024A#A006A706C406C406
+
+    $ cat candump-2021-01-04_180521.log | cantools plot tests/files/dbc/abs.dbc
+
+.. image:: docs/plot-1.png
+
+If you don't want to show all signals you can select the desired signals with command line arguments.
+A ``*`` can stand for any number of any character, a ``?`` for exactly one arbitrary character.
+Signals separated by a ``-`` are displayed in separate subplots.
+Optionally a format can be specified after a signal, separated by a colon.
+
+.. code-block:: bash
+
+    $ cat candump-2021-01-04_180521.log | cantools plot tests/files/dbc/abs.dbc '*33.*fl:-<' '*33.*fr:->' - '*33.*rl:-<' '*33.*rr:->'
+
+.. image:: docs/plot-2.png
+
+For more information see
+
+.. code-block:: bash
+
+    $ cantools plot --help
+
 The dump subcommand
 ^^^^^^^^^^^^^^^^^^^
 
@@ -343,3 +385,5 @@ Contributing
 .. _motohawk_no_floating_point_numbers.h: https://github.com/eerimoq/cantools/blob/master/tests/files/c_source/motohawk_no_floating_point_numbers.h
 
 .. _motohawk_no_floating_point_numbers.c: https://github.com/eerimoq/cantools/blob/master/tests/files/c_source/motohawk_no_floating_point_numbers.c
+
+.. _matplotlib: https://matplotlib.org/
diff --git a/cantools/__init__.py b/cantools/__init__.py
@@ -35,12 +35,14 @@ def _main():
     from .subparsers import dump
     from .subparsers import convert
     from .subparsers import generate_c_source
+    from .subparsers import plot
 
     decode.add_subparser(subparsers)
     monitor.add_subparser(subparsers)
     dump.add_subparser(subparsers)
     convert.add_subparser(subparsers)
     generate_c_source.add_subparser(subparsers)
+    plot.add_subparser(subparsers)
 
     args = parser.parse_args()