Realtime Plots with Pyqtgraph

This generates five sets of random data using the RandomWalkDataSource and plots them in realtime as traces on a pyqtgraph plot using PyqtgraphDataSink.

The plotlayout parameter demonstrates setting up two stacked plot panels and styling the five traces.

recipes/randomwalk_pyqtgraph.config

[datalogd]
connection_graph =
  digraph {
    a [class=RandomWalkDataSource, interval=0.03, walkers="[[5.6, 0.10], [7.8, 0.15], [9.0, 0.25], [12345, 45], [12345, 67]]"];
    s [class=PyqtgraphDataSink, npoints=1024, title="Pyqtgraph Plots", size="[1000, 800]", plotlayout="
      [
        {
          'ylabel': 'Temperature (℃)',
          'traces': [
            {
              'name': 'Trace 1',
              'pen': [255, 0, 0],
              'selector': [
                ['type', 'randomwalk'],
                ['id', '0']
              ]
            },
            {
              'name': 'Trace 2',
              'pen': [0, 255, 0],
              'selector': [
                ['type', 'randomwalk'],
                ['id', '1']
              ]
            },
            {
              'name': 'Trace 3',
              'pen': [0, 0, 255],
              'selector': [
                ['type', 'randomwalk'],
                ['id', '2']
              ]
            }
          ]
        },
        {
          'ylabel': 'Pressure (kPa)',
          'traces': [
            {
              'name': 'Trace 4',
              'pen': [255, 255, 0],
              'selector': [
                ['type', 'randomwalk'],
                ['id', '3']
              ]
            },
            {
              'name': 'Trace 5',
              'pen': [255, 0, 255],
              'selector': [
                ['type', 'randomwalk'],
                ['id', '4']
              ]
            }
          ]
        }
      ]
    "];
    a -> s;
  }

$ datalogd -c recipes/randomwalk_pyqtgraph.config

INFO:main:Initialising DataLogDaemon.
INFO:DataLogDaemon:Loaded config from: recipes/randomwalk_pyqtgraph.config
INFO:pluginlib:Loading plugins from standard library
INFO:DataLogDaemon:Detected source plugins: NullDataSource, PicoTC08DataSource, RandomWalkDataSource, SerialDataSource
INFO:DataLogDaemon:Detected filter plugins: NullDataFilter, AggregatorDataFilter, CoolingPowerDataFilter, CSVDataFilter, FlowSensorCalibrationDataFilter, JoinDataFilter, KeyValDataFilter, PolynomialFunctionDataFilter, TimeStampDataFilter
INFO:DataLogDaemon:Detected sink plugins: NullDataSink, FileDataSink, InfluxDB2DataSink, LoggingDataSink, MatplotlibDataSink, PrintDataSink, PyqtgraphDataSink
INFO:DataLogDaemon:Initialising node a:RandomWalkDataSource(interval=0.03, walkers=[[5.6, 0.1], [7.8, 0.15], [9.0, 0.25], [12345, 45], [12345, 67]])
INFO:DataLogDaemon:Initialising node s:PyqtgraphDataSink(npoints=1024, title=Pyqtgraph Plots, size=[1000, 800], plotlayout=[{'ylabel': 'Temperature (℃)', 'traces': [{'name': 'Trace 1', 'pen': [255, 0, 0], 'selector': [['type', 'randomwalk'], ['id', '0']]}, {'name': 'Trace 2', 'pen': [0, 255, 0], 'selector': [['type', 'randomwalk'], ['id', '1']]}, {'name': 'Trace 3', 'pen': [0, 0, 255], 'selector': [['type', 'randomwalk'], ['id', '2']]}]}, {'ylabel': 'Pressure (kPa)', 'traces': [{'name': 'Trace 4', 'pen': [255, 255, 0], 'selector': [['type', 'randomwalk'], ['id', '3']]}, {'name': 'Trace 5', 'pen': [255, 0, 255], 'selector': [['type', 'randomwalk'], ['id', '4']]}]}])
INFO:DataLogDaemon:Connecting a:RandomWalkDataSource -> s:PyqtgraphDataSink
INFO:main:Starting event loop.