IIR Filter without using a loopm t

[Ken Kearney]

I'm trying to apply an IIR filter equation to a large array and for this reason I don't want to use a FOR loop - because it takes forever to get through the array. Is is possible to do this using array functions? I have done similar things for FIR filters but it's the use of previous output values that has me stumped.

Can anybody help?

Thanks,

Ken

[DSPGuy]

Ken,

There are two VIs that should be available to help with this.  Look for IIR Cascade Filter.vi and IIR Filter.vi.  Both implement the filter with the coefficients being inputs.  The difference is in the layout of the coefficients.  IIR Filter.vi uses direct form, IIR Cascade Filter.vi uses cascaded 2nd or 4th order stages.  The layout for both structures can be found in the online help.

-Jim