Using NaNs with filter operations

[pri]

Is there any filter block in LabVIEW 8.0 that deals with NaNs or spaces? We are using NaNs in place of missing data points for the raw data. When the filter (Butterworth order 4) sees a NaN, it just stops filtering any further or just put in NaNs for all the other data points. So we replaced NaNs with zeros but does not seem to solve the problem.

Please help.

Thank you.

[ShotSimon]

Please post your code.  In 8.5 I recently encountered a similar issue with and Agilent USB power meter.   I have 6i at home so I can't see it, but I recall a NaN constant which I ended up using with a conditional to remove the NaN data which was being coerced into a 0.0 of type double.  There may even be a conditional that deals with the NaN direct.  Is this what you are referring to?

[ryan_d]

Hi pri,

LabVIEW has a "Not a Number/Path/Refnum?" comparison operator that will return true if the input wire is NaN. You can use this in conjuction with a Point-by-Point Butterworth filter to handle the NaNs.


Message Edited by ryan_d on 12-20-2007 02:35 PM

[pri]

Thank you I'll try to do that.