Simulink: how to define variable that will remain constant during duration of simulation and use in MATLAB function blocks

I am trying to run a custom recursive least squares block and want to be able to configure the filter order N from a config file.

The value of the filter order will remain constant for the entire simulation. How can I create functions that:

a) produce a vector of N past values to act as the regressor

b) fit the parameters to the data

Currently simulink is giving errors because the vector of regressors and parameters are of variable size, (which is not true within any single simulation run). How can I get around this issue without having to go through a large number of blocks and set up all these signals as variable sized?

Answer 1

[Paul]

For part a), a Tapped Delay block seems like it meets the need.

For part b), in the absence of any other information, feed the oiutput fo the Tapped Delay block into a Matlab Function to do the fitting.

[Sebastian]

Thank you very much!