How to load pre-calculated matrix value in a file into Simulink for simulation ?

Hello,

We have a Matlab program to calculate a matrix and save it in a .mat file (using save(filename,'Matrix-Variable')). Now we want to use it in Simulink for simulation. What is the best way to do this ?

I am using the Matlab Function in Simulink and what to use load() command to load the matrix value. This works in Matlab workspace. But it seems dones't work for Simulink. Attached is the simple code. I always get 0 output (the real elment is another constant value) for y when I run the simulation.

Any suggestions and help will be highly appreciated. Thanks.

%This is a Matlab funciton block in Simulink. % % Try to read matrix R value from the file (fileR.mat) %

function y = fcn(init,u)

coder.extrinsic('load') coder.extrinsic('disp') filename = 'fileR'; %need to define the varible R (18x9) matrix R=zeros(18,9);

%The matrix R value is saved in the file already. Just want to load it load(filename, 'R');

%check the first element to see if the load is correct y = R(1,1); disp(y); end

Answer 1

[Titus Edelhofer]

Hi Tom,

if it is a constant matrix I would do the following: add the load command to the preload function of the model (menu File->Model properties->Callbacks, write

load myfile.mat

and use the constant block with the name of the matrix in the file as parameter.

Titus

[Tom]

Thank you Titus. This is exactly what I am looking for. It works.

Answer 2

[Titus Edelhofer]

Hi Tom,

I would use the From File block to directly work with the matrix in the file. You would just need to make sure it has the right format (time and values, see the doc).

Titus

Answer 3

[Tom]

Hi Titus,

Thank you for the quick reponse. I looked the From file block and was not sure what to do with the first rom, which should be time value. For my case, this is a constant matrix. Maybe I mis-understanded something there.

Thanks,

Tom