What is the equivalent of Discrete Filter bloc in a matlab code ?

Question

Guilhem Schena 2021-6-29

0
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https://ww2.mathworks.cn/matlabcentral/answers/867868-what-is-the-equivalent-of-discrete-filter-bloc-in-a-matlab-code

回答： Andy Bartlett 2021-6-30

I am trying to convert a simulink model into a matlab code, but I don't know how I can write the Discrete Filter bloc (DSP System toolbox).

I have made a Matlab class to run my code through a simulation to compare the code I wrote with the Discrete Filter bloc, here are the stepImpl() and resetImpl() methods of it :

function u = stepImpl(obj, s)
            obj.s_vect = circshift(obj.s_vect, 1);
            obj.s_vect(1) = s;
            obj.u = conv(obj.s_vect, obj.w, 'same');
            u = obj.u(1);
        end
        function resetImpl(obj)
            % Initialize / reset discrete-state properties
            
            obj.w = [1 2 3 4 5 6];
            obj.u = [0 0 0 0 0 0];
            obj.s_vect = [0 0 0 0 0 0];
        end

And here is my simulink model to compare the result :

The coefficients of my vector obj.w is the same as the numerator of the discrete filter :

The result are a sine wave oscillating between -10 and 10 for the matlab class, while it is an sine wave oscillating from -20 to 20 for the bloc. I want my matlab class to provide the same result as the simulink bloc.

I have no idea if the function conv() is made for this, and I am not sure neither if the way to manage input and output signal is correct.

Can you help me ?

Thank you !