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Display object tracks on bird's-eye plot


plotTrack(tPlotter,positions) displays object tracks from a list of object positions on a bird's-eye plot. The track plotter, tPlotter, is associated with a birdsEyePlot object and configures the display of the object tracks.

To remove all tracks associated with track plotter tPlotter, call the clearData function and specify tPlotter as the input argument.

plotTrack(tPlotter,positions,velocities) displays tracks and their velocities on a bird's-eye plot.

plotTrack(tPlotter,positions,labels) displays tracks and their labels on a bird's-eye plot.

plotTrack(tPlotter,positions,covariances) displays tracks and the covariances of track uncertainties on a bird's-eye plot.


plotTrack(tPlotter,positions,velocities,labels,covariances) displays tracks and their velocities, labels, and covariances on a bird's-eye plot. You can specify one or more of velocities, labels, and covariances. These arguments can appear in any order but they must come after tPlotter and positions.


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Create a bird's-eye plot with an x-axis range from 0 to 90 meters and a y-axis range from –35 to 35 meters. Create a track plotter that displays up to seven history values for each track and offsets labels by 3 meters in front of the tracks.

bep = birdsEyePlot('XLim',[0 90],'YLim',[-35 35]);
tPlotter = trackPlotter(bep,'DisplayName','Tracks','HistoryDepth',7,'LabelOffset',[3 0]);

Set the positions and velocities of three labeled tracks.

positions = [30, 5; 30, 5; 30, 5];
velocities = [3, 0; 3, 2; 3, -3];
labels = {'T1','T2','T3'};

Display the tracks for 10 trials. The bird's-eye plot shows the seven history values specified previously.

for i=1:10
   positions = positions + velocities;

Input Arguments

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Track plotter, specified as a TrackPlotter object. This object is stored in the Plotters property of a birdsEyePlot object and configures the display of the specified tracks in the bird's-eye plot. To create this object, use the trackPlotter function.

Positions of tracked objects in vehicle coordinates, specified as an M-by-2 real-valued matrix of (X, Y) positions. M is the number of tracked objects. The positive X-direction points ahead of the center of the vehicle. The positive y-direction points to the left of the origin of the vehicle, which is the center of the rear axle, as shown in this figure of the vehicle coordinate system.

Vehicle with X-axis, Y-axis, and origin labeled

Velocities of tracked objects, specified as an M-by-2 real-valued matrix of velocities in the (X, Y) direction. M is the number of tracked objects. The velocities are plotted as line vectors that originate from the center positions of the tracked objects.

Track labels, specified as an M-length string array or an M-length cell array of character vectors. M is the number of tracked objects. The labels correspond to the locations in the positions matrix. By default, tracks do not have labels. To remove all annotations and labels associated with the track plotter, use the clearData function.

Covariances of track uncertainties centered at the track positions, specified as a 2-by-2-by-M real-valued array. The uncertainties are plotted as an ellipse.

Version History

Introduced in R2017a