trackMetricsTable

Compare tracks to truth

Syntax

metricsTable = trackMetricsTable(assignmentMetric)

Description

metricsTable = trackMetricsTable(assignmentMetric) returns a table of metrics, metricsTable, for all tracks in the track assignment metrics object, assignmentMetric.

Examples

Assignment and Error Metrics for Two Tracked Targets

Examine the assignments and errors for a system tracking two targets.

First, load the stored track data.

load trackmetricex tracklog truthlog

Create objects to analyze assignment and error metrics.

tam = trackAssignmentMetrics;
tem = trackErrorMetrics;

Create the output variables.

posRMSE = zeros(numel(tracklog),1);
velRMSE = zeros(numel(tracklog),1);
posANEES = zeros(numel(tracklog),1);
velANEES = zeros(numel(tracklog),1);

Loop over all tracks to:

• Extract the tracks and ground truth at the i th tracker update.

• Analyze and retrieve the current track-to-truth assignment.

• Analyze instantaneous error metrics over all tracks and truths.

for i=1:numel(tracklog)
    tracks = tracklog{i};
    truths = truthlog{i};
    [trackAM,truthAM] = tam(tracks, truths);
    [trackIDs,truthIDs] = currentAssignment(tam);
    [posRMSE(i),velRMSE(i),posANEES(i),velANEES(i)] = ...
        tem(tracks,trackIDs,truths,truthIDs);
end

Show the track metrics table.

trackMetricsTable(tam)

ans=4×16 table
    TrackID    AssignedTruthID    Surviving    TotalLength    UnreportedStatus    DeletionStatus    DeletionLength    DivergenceStatus    DivergenceCount    DivergenceLength    RedundancyStatus    RedundancyCount    RedundancyLength    FalseTrackStatus    FalseTrackLength    SwapCount
    _______    _______________    _________    ___________    ________________    ______________    ______________    ________________    _______________    ________________    ________________    _______________    ________________    ________________    ________________    _________

       1             NaN            false         1120             false              false               0                false                 3                   3                false                 0                   0                false                  0               0    
       2             NaN            false         1736             false              false               0                false                 8                  88                false                 0                   0                false                 28               3    
       6               3            true          1138             false              false               0                false                 4                 314                false                 1                  28                false                  0               2    
       8               2            true           662             false              false               0                false                 2                  29                false                 1                 169                false                 28               0    

Show the truth metrics table.

truthMetricsTable(tam)

ans=2×11 table
    TruthID    AssociatedTrackID    DeletionStatus    TotalLength    UnreportedStatus    BreakStatus    BreakCount    BreakLength    InCoverageArea    EstablishmentStatus    EstablishmentLength
    _______    _________________    ______________    ___________    ________________    ___________    __________    ___________    ______________    ___________________    ___________________

       2               8                false            2678             false             false           4             168            true                 true                    56         
       3               6                false            2678             false             false           3             645            true                 true                    84         

Plot the RMSE and ANEES error metrics.

subplot(2,2,1)
plot(posRMSE)
title('Position Error')
xlabel('tracker update')
ylabel('RMSE (m)')

subplot(2,2,2)
plot(velRMSE)
title('Velocity Error')
xlabel('tracker update')
ylabel('RMSE (m/s)')

subplot(2,2,3)
plot(posANEES)
title('Position Error')
xlabel('tracker update')
ylabel('ANEES')

subplot(2,2,4)
plot(velANEES)
title('Velocity Error')
xlabel('tracker update')
ylabel('ANEES')

Show the current error metrics for each individual recorded track.

currentTrackMetrics(tem)

ans=2×5 table
    TrackID    posRMS    velRMS    posANEES    velANEES
    _______    ______    ______    ________    ________

       6       44.712    20.988    0.05974     0.31325 
       8       129.26    12.739     1.6745      0.2453 

Show the current error metrics for each individual recorded truth object.

currentTruthMetrics(tem)

ans=2×5 table
    TruthID    posRMS    velRMS    posANEES    velANEES
    _______    ______    ______    ________    ________

       2       129.26    12.739     1.6745      0.2453 
       3       44.712    20.988    0.05974     0.31325 

Show the cumulative error metrics for each individual recorded track.

cumulativeTrackMetrics(tem)

ans=4×5 table
    TrackID    posRMS    velRMS    posANEES    velANEES
    _______    ______    ______    ________    ________

       1       117.69    43.951    0.58338     0.44127 
       2        129.7      42.8    0.81094     0.42509 
       6       371.35    87.083     4.5208      1.6952 
       8       130.45    53.914     1.0448     0.44813 

Show the cumulative error metrics for each individual recorded truth object.

cumulativeTruthMetrics(tem)

ans=2×5 table
    TruthID    posRMS    velRMS    posANEES    velANEES
    _______    ______    ______    ________    ________

       2       258.21    65.078     2.2514     0.93359 
       3       134.41    48.253    0.96314     0.49183 

Input Arguments

assignmentMetric — Track assignment metrics object

trackAssignmentMetrics System object

Track assignment metrics object, specified as a trackAssignmentMetrics System object™.

Output Arguments

metricsTable — Track metrics table

table

Track metrics table, returned as a table. Each row of the table represents a track. The table has these columns:

Column	Description
TrackID	Unique track identifier
AssignedTruthID	Unique truth identifier. If the track is not assigned to any truth, or the track was not reported in the last update, then the value of AssignedTruthID is NaN.
Surviving	True if the track was reported in the last update
TotalLength	Number of updates in which this track was reported
UnreportedStatus	True if the track was not reported in the current update
MaxTimeBetweenReports	The maximum time interval between adjacent updates to this track. To enable this field, set the MaxUnreportedPeriod property of the metric to a non-zero value. The field is returned as a NaN value if there was only one update to this track.
MeanTimeBetweenReports	The average time interval between adjacent updates to this track. To enable this field, set the MaxUnreportedPeriod property of the metric to a non-zero value. The field is returned as a NaN value if there was only one update to this track.
DeletionStatus	True if the track was previously assigned to a truth that was deleted while inside its coverage area.
DeletionLength	The number of updates in which the track was following a deleted truth
DivergenceStatus	True when the divergence distance between this track and its corresponding truth exceeds the divergence threshold
DivergenceCount	Number of times this track entered a divergent state
DivergenceLength	Number of updates in which this track was in a divergent state
RedundancyStatus	True if this track is assigned to a truth already associated with another track
RedundancyCount	Number of times this track entered a redundant state
RedundancyLength	Number of updates for which this track was in a redundant state
FalseTrackStatus	True if the track was not assigned to any truth
FalseTrackLength	Number of updates in which the track was unassigned
SwapCount	Number of times the track was assigned to a new truth object

Version History

Introduced in R2018b