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Pause code execution to achieve desired execution rate



waitfor(rate) pauses execution until the code reaches the desired execution rate. The function accounts for the time that is spent executing code between waitfor calls.

numMisses = waitfor(rate) returns the number of iterations missed while executing code between calls.


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Create a rate object that runs at 1 Hz.

r = rateControl(1);

Start a loop using the rateControl object inside to control the loop execution. Reset the object prior to the loop execution to reset timer. Print the iteration and time elapsed.

for i = 1:10
	time = r.TotalElapsedTime;
	fprintf('Iteration: %d - Time Elapsed: %f\n',i,time)
Iteration: 1 - Time Elapsed: 0.001485
Iteration: 2 - Time Elapsed: 1.001106
Iteration: 3 - Time Elapsed: 2.000637
Iteration: 4 - Time Elapsed: 3.000937
Iteration: 5 - Time Elapsed: 4.001071
Iteration: 6 - Time Elapsed: 5.001071
Iteration: 7 - Time Elapsed: 6.000925
Iteration: 8 - Time Elapsed: 7.000560
Iteration: 9 - Time Elapsed: 8.000385
Iteration: 10 - Time Elapsed: 9.000394

Each iteration executes at a 1-second interval.

Input Arguments

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Rate object, specified as a handle. This object contains the information for the desired rate and other information about the execution. See rateControl (Navigation Toolbox) for more information.

Output Arguments

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Number of missed task executions, returned as a scalar. waitfor returns the number of times the task was missed in the Rate object based on the LastPeriod time. For example, if the desired rate is 1 Hz and the last period was 3.2 seconds, numMisses returns 3.

Version History

Introduced in R2016a

See Also

| (Navigation Toolbox)