how to use ha.coefficients for a filter?

I am using the code below which works but if I try to filter the input with the ha.coefficients I don't get the desired signal. How do I use the coefficients and the matlab filter command to filter the input stored in xx to get the desired output d?

mu=.008; ha = adaptfilt.lms(250,mu); [yy,e] = filter(ha,xx(1:250),d);

I tried to desired = filter(ha.coefficients,1,xx(1:250));

Answer 1

[Honglei Chen]

It's an adaptive filter so the coefficients changes at every step. The Coefficients only contains the initial coefficients. In addition, the setup for adaptive filter is often in a vectorized form so filter is often carried out using matrix multiplication than the difference equation implemented in the filter command.

[dgmn]

I am trying to identify a unknown system/filter using LMS. I thought adaptfilt.lms would provide filter coefficents that I could use with the filter command. Is there a recommended way to do this?

Thanks

[Honglei Chen]

What version do you have? You can try the new dsp.LMSFilter which you can get the the coefficients by set WeightsOutputPort to true. But nevertheless, I don't think you want to use filter with those coefficients, you should just use in matrix multiplication.