Live Plotting

The framework exists for simulations to be run with an option to plot data continuously. Resulting plots are not plotted with the same precision as the final plots, therefore should be used qualitatively. This document gives an overview of the options, and how to use live plotting in simulations.

Templates

Reference implementations / templates for live plotting exist for bskSim scenarios at scenario_BasicOrbit_LivePlot.py and for regular scenarios at scenarioBasicOrbitLivePlot.py. The same implementation can be used for any scenario within Basilisk.

Defining Live and Final Plots

Using a bskSim Scenario

The data structure that contains all information for what to plot live is contained in dataRequests:

dataRequests = [{"plotID" : 0,
                 "plotFun" : "plot_orbit",
                 "dataReq" : [self.masterSim.get_DynModel().simpleNavObject.outputTransName + ".r_BN_N"]},
                {"plotID" : 1,
                 "plotFun" : "plot_orientation",
                 "dataReq" : [self.masterSim.get_DynModel().simpleNavObject.outputTransName + ".r_BN_N",
                              self.masterSim.get_DynModel().simpleNavObject.outputTransName + ".v_BN_N",
                              self.masterSim.get_DynModel().simpleNavObject.outputAttName + ".sigma_BN"]}]

  • plotID = unique plot identifier

  • plotFun = name of plotting function in bskSimScenarios/plotting/BSK_Plotting.py to use

  • dataReq = data to be pulled from simulation

Using a BSK scenario without bskSim

dataRequests = [{"plotID" : None,
                 "plotFun" : None,
                 "dataReq" : [scObject.scStateOutMsgName + '.r_BN_N',
                              scObject.scStateOutMsgName + '.v_BN_N']}]

dataReq will contain all data points wanted for plotting. Plots are defined in the scenario script therefore plotID and plotFun can be left empty.

How To Live Plot / Adapt the Template

The only user-defined elements to adopt are:

  1. Defining Data to Plot

    • Fill in dataReq with required information.

  2. (For Scenarios Only): Define Plotting Function

    • Create a plotting function and migrate plotting code.

    • Execute simulation with arguments:

      • showPlots = boolean

      • livePlots = boolean

      • simComm = simulation side of communication pipe

      • plottingFunc = created function containing plotting

      • `plotArgs` = list of arguments for plottingFunc

Refresh Rate

The scenario contains method live_outputs(self, plotComm, rate). Here, rate is defined in ms and dictates how often the scenario will request data from the simulation to plot.

Note

In the case of multiple simultaneous live plots, the rate at which any one plot will be updated will be approximately rate/# of plots.

Running Without Live Plots

The scenario’s member livePlots is a boolean that can be set to False to retain original scenario functionality.

Warning

On macOS there is a NSXPCSharedListener warning of invalid connection. This does not effect performance and is under attention.