I am looking for a filter funtion that behaves similarly to the "FiltFilt" function within MatLab. I have attached a description of the MatLab "FiltFilt" function. So far I have been unable to find a similar filter.
There does not seem to be a direct zero-phase filter method availabe, but this can still certainly be implemented.
However, you can use any of the filtering methods available in the digital filter namespace, along with a few simple programming techniques to implement this fileter (see NationalInstruments.Analysis.DSP.Filters Namespace in the NI Measurement Studio Help for more information on available filters).
The following post is from the LabVIEW discussion forum, but it is a general programming discussion which directly applies to your issue: http://forums.ni.com/ni/board/message?board.id=170&message.id=40033
Please let me know if you have any other questions.
Have a great day!
Andrew W || Applications Engineer National Instruments