topic Re: filter array in LabVIEW

filter array

Tohatsu — Tue, 04 Dec 2007 12:50:23 GMT

I have 4 inputs channels, each containing 8 values (32 channels), and I want to meanfilter each channel all with the same filterlength...I know this seems like a very newish question, but in that case, the reply should be realtivly easy too 😉

see image for details

Re: filter array

andre.buurman@carya — Tue, 04 Dec 2007 17:40:29 GMT

Duplicate post

If you need to add more info you can either "Edit the post" or post a reply to your previous post.

Message Edited by Support on 12-04-2007 11:40 AM

Re: filter array

Tohatsu — Tue, 04 Dec 2007 14:09:28 GMT

look at the times, they were posted simultaneously, could not find a delete, flagged it to the moderators...sorry

Re: filter array

Laura F. — Tue, 04 Dec 2007 17:38:53 GMT

Hi all,

I removed the duplicate post, so I am sure Tohatsu would appreciate any help given on this thread.

Regards,
Laura
Web Support & Operations
National Instruments

Re: filter array

andre.buurman@carya — Wed, 05 Dec 2007 07:46:05 GMT

You could use the point by point VI in the Signal Processing palette.

Re: filter array

Tohatsu — Thu, 13 Dec 2007 07:41:14 GMT

Yes, and that is what I've been doing for testing puropses, but I dont want 32 of them lying around in my VI...but maybe that's the only solution?

Re: filter array

altenbach — Thu, 13 Dec 2007 07:52:56 GMT

Repetitive task with a fixed number of iterations typically call for a FOR loop and one instance of the code. Could you show a bit more of your VI or even attach it?

Re: filter array

Tohatsu — Thu, 13 Dec 2007 09:04:39 GMT

Attached VI

Re: filter array

Tohatsu — Mon, 17 Dec 2007 08:49:59 GMT

Bump

tried some for-loops, but it seems I must be doing something wrong...cause all the data is just messed up with this method.

Message Edited by Tohatsu on 12-17-2007 02:49 AM

Re: filter array

altenbach — Mon, 17 Dec 2007 15:44:25 GMT

The NI pt-by-pt mean filter is reentrant, so using it in a FOR loop on 32 channels will not work as expected. You would still need 32 instances, one for each channel.

The pt-by-pt meanfilter is a plain VI, meaning you can modify it for your own purpose. Make a copy of it under a new name and change it such that it takes an array as input and will do a meanfiltering operation on each element (channel). Shouldn't be too difficult. 🙂

Re: filter array

Tohatsu — Tue, 18 Dec 2007 09:42:15 GMT

well, I opened that VI, and I can tell you it's way beyond my understanding to modify that to take an array instead.

Guess I'll have to split ti up into 32 channels then...because I also want to make calibration adjustments to the readings. Calibration data read from a file, then interpreted into a polynom and then compensate the reading

Anders