Simulink Control Design™ - MathWorks

Input-Signal-Specific Ways to Avoid Memory Issues

To avoid memory issues, try one or more of the actions listed in the following table, as

appropriate for your input signal type.

Input Signal Type Action

Sinestream • Remove low frequencies from your input

signal for which you do not need the

frequency response.

• Modify the sinestream signal to estimate
  each frequency separately by setting the
  SimulationOrder option to
  OneAtATime. Then estimate using a
  frestimate syntax that does not
  request the simulated time-response
  output data, for example sysest =
  frestimate(model,io,input).


• Use parallel computing to run
  independent simulations in parallel on
  different computers. See “Speeding Up
  Estimation Using Parallel Computing”
  on page 5-83.


• Divide the input signal into multiple
  signals using fselect. Estimate the
  frequency response for each signal
  separately using frestimate. Then,
  combine results using fcat.
  Chirp Create separate input signals that divide up
  the swept frequency range of the original
  signal into smaller sections using
  frest.Chirp. Estimate the frequency
  response for each signal separately using
  frestimate. Then, combine results using
  fcat.
  Random Decrease the number of samples in the
  random input signal by changing
  NumSamples before estimating. See “Time
  Response Is Noisy” on page 5-57.

5 Frequency Response Estimation