B,A parameters in Shelving Filter design

Thank you in advance for your attention.

I guess that my question is quite easy but I just want to make sure that I am right...

I am trying to implement a shelving filter, and I have found a matlab command on the internet which does exactly what I need.

http://www.mathworks.com/matlabcentral/fileexchange/16568-bass-treble-shelving-filter

The problem is that my matlab release, 7.12 doesn´t recognize this command and I dont know what´s going on...

I know that other commands such as fdesign generates all kind of filters... but I need to get B and A coefficients of the filter specified.

Regards,

Luis.

[Amith Kamath]

Going through the code in the link you've provided, it doesn't look like there is any function that could be Matlab version dependent. Could you please also include what error message you get when you run the code?

[Luis Gomez]

1.-When I try to ask for help on the command line...

">> help shelving

shelving not found.

Use the Help browser search field to search the documentation, or type "help help" for help command options, such as help for methods."

2.-When I try to execute directly this command with some values on its inputs...

>> [B,A]=shelving(5,0.2,40000,1,'Treble_Shelf');

??? Undefined function or method 'shelving' for input arguments of type 'double'.

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

[B,A] = shelving(G, Fc, Fs, Q, type);

            G is the logrithmic gain (in dB) 
            FC is the center frequency 
            Fs is the sampling rate 
            Q adjusts the slope be replacing the sqrt(2) term 
            type is a character string defining filter type 
                 Choices are: 'Base_Shelf' or 'Treble_Shelf'

[Walter Roberson]

Did you download the code from that link, and put it in a directory that is on your MATLAB path? You can use pathtool to adjust your MATLAB path.

[Luis Gomez]

Thank you so much Walter,

I didn´t notice that it was a function and I had to download and copy it in my workspace... I guess that it will work

[John]

Hello guys does anyone know what K = tan((pi * fc)/fs); (its in the code of shleving filter) thangs

Answer 1

[John]

Hello guys does anyone know what K = tan((pi * fc)/fs); (its in the code of shleving filter) thangs