# response of algorithm in non-equidistant time

We are investigating ways to test a control algorithm. The algorithm has a non-equidistant track of input data (i.e. not every sample is valid, and we know it), and should output a series of correction factors.

Under a certain frequency, it should correct for a deteriorating light source.

Is there a way to black-box test the algorithm's transfer function? I'm having trouble especially with the fact that it's non-equidistant.

The goal of the tests would be to have a clear idea on the algorithm's behavior in terms of

• delay/phase response
• resonances
• frequency response

So I was actually dreaming of a kind of a 'swept sine' test, or an impulse response, or something alike, but I'm a bit lost in what is feasible with non-equidistant signals.

• Is it the case that the input samples are equidistant, but random samples are missing? Is the system to produce correction factors at equidistant increments in time? – user2718 Mar 14 '13 at 13:45
• @BZ: input data is 'quite' equidistant, and some samples are missing, yes. – xtofl Mar 14 '13 at 14:19
• @BZ: the output cadence is not really important, but will probably be in pace with the input. – xtofl Mar 14 '13 at 14:20
• Is is possible to do interpolation to fill in the missing input samples? – user2718 Mar 14 '13 at 17:42
• Can you specify what you mean by "black box" test the transfer function? Do you want to run standard control signals and get step response, impulse response, oscillatory response etc... open loop, closed loop? Test for regulation with disturbances in the light source transducer signal? What is your goal in testing? – user2718 Mar 15 '13 at 19:35

• i up-arrowed you, @BZ. the non-uniform sampling is a bitchy sorta problem. if you knew that every $N$th sample was missing (a uniform non-uniformity), then there is an exact way to deal with the problem as long as there is no signal content above $\frac{N-1}{N} \ \frac{f_s}{2}$ . – robert bristow-johnson Jan 10 '14 at 2:38