how to get filter coefficients after designing filter in FDA tool

Hello, I have designed a bandpass filter as suggested here as below

   d = fdesign.bandpass('Fst1,Fp1,Fp2,Fst2,Ast1,Ap,Ast2',0.5,1,3,4,80,0.5,80,50);
   Hd = design(d,'butter');

here but with fda toool and now I need only the filter coefficients as they will be used for designing filter microcontroller. I am confused with the two options available with the export

1)objects:results 'Hd' variables in the workspace

2)coefficients:results G,SOS variables in the workspace

Which one should I use and how to get and see only the original filters coefficients so that I can copy them into notepad.

Can anyone explain about this. Thanks.

Answer 1

[Honglei Chen]

If you want the coefficients, you should use second option, "coefficients".

If you choose first option, you get a filter specified in Hd. You can perform the filtering operation by calling filter(Hd,x), but Hd itself is an object describing the filter. It is more than the mere filter coefficients.

HTH

[Stefan]

Thanks and I guess the 'G' contains the actual coefficients that are needed from two variables G and SOS that are exported to the wokspace..