Why do I receive an error message "Value must be a scalar" using the FDESIGN.DECIMATOR function in Filter Design Toolbox 3.3 (R14SP3)?

When I enter the following in MATLAB 7.1 (R14SP3):

>> hs = fdesign.decimator(5,'CIC','fp,ast',0.55,55)

I receive the following error message:

 ??? Error using ==> sigdatatypes.schema>check_singular

 Value must be a scalar.

Answer 1

[MathWorks Support Team]

This bug has been fixed in Release 2006a (R2006a). For previous product releases, read below for any possible workarounds:

This is an error in the documentation for FDESIGN.DECIMATOR in the Filter Design Toolbox 3.3 (R14SP3). To construct a CIC decimator, you have to specify the differential delay input argument, "d", for the CIC filter as well as the other input values. Here is the correct syntax adding the differential delay argument:

d = 1; %Differential delay.

s = fdesign.decimator(5,'CIC',d, 'fp,ast',0.55,55);

Note the additional input argument "d" used to specify the differential delay immediately after the CIC argument string. The examples in the documentation are otherwise correct.