How to use unsupported function when using Coder

Hi,

I wanna use fdesign.audioweighting('WT','ITUT041',..) and design() function. However both of them are not supported by Matlab coder.

How can i create C .dll with these function in 2023a?

Answer 1

[Kanishk]

Hi @BERKAY,

Yes, ‘fdesign.audioweighting’ is not supported by MATLAB coder for code generation. But you can follow a hybrid approach. This involves designing the filter in MATLAB, extracting the filter coefficients, and then using these coefficients in a MATLAB function that can be converted to C code.

d = fdesign.audioweighting('WT', 'ITUT041'); 
Hd = design(d, 'butter'); 
[b, a] = tf(Hd); 
save('filterCoefficients.mat', 'b', 'a'); 

You can use these saved variables with ‘filter’ function which is supported by MATLAB coder for code generation.

filter(b, a, x);

To load variables from MAT file during compile time in MATLAB Coder see ‘coder.load’: https://www.mathworks.com/help/simulink/slref/coder.load.html

Also to learn more about ‘filter’ function you can refer: https://www.mathworks.com/help/releases/R2024a/matlab/ref/filter.html