point by point bandpass filter with bandpass frequencies slowly changing with time

[TulaRen]

I have a need to (ptBypt) band-pass filter a signal, but the band pass frequencies vary slowly with time, e.g., the band pass frequencies change linearly from 5-10 Hz to 10-20 Hz in 30 seconds. Can this be done?

Thanks.

Ian 

[crossrulz]

You could use the Ramp Pattern.vi for generating your friequencies for your filter and then use one of the PtByPt Filter VIs to do your bandpass filter inside of a FOR loop.  Should not be hard.

[TulaRen]

Well, unless I initialize the filter, I cannot really alter the band pass frequencies. But if I initialize the filter, it resets everything.

[TulaRen]

using "FIR Filter with I.C." seems to work, but I cannot find the byBypt version for FIR filter.  

[JLewis]

If you look inside the FIR Filter PtByPt.vi you can see how it uses the IIR Filter with I.C. PtByPt.vi with an empty array of reverse coefficients.