Coherence Function

[Chante01]

With only one set of data it is mathematically possible to calculate the coherence function.  How do I calculate the correct coherence function in LabVIEW with only one set of data?

[Matt_S.]

Howdy Chante,

The coherence function is comparing two sets of data, so you'd definitely need both sets of data. What do you want to compare the original set of data to? You could produce your own data set to use as a secondary input. Let us know why you want to use this function with only one input. It's quite possible there's a better solution for you.

Regards,
Matt S.

[Chante01]

Hey Matt,

Thanks for the response.  However, I am providing two sets of data; a stimulus and a response.  I meant to say I only have one set of stimulus data and one set of response data that is being read from a file.  The coherence function won't calculate the correct coherence without averaging.  I'm always getting a coherence of one. 

Therefore, how do I read in multiple sets of data to enable averaging which seems to be needed in order to calculate the coherence?

[Matt_S.]

Hi Chante,

See the following forum post.

http://forums.ni.com/ni/board/message?board.id=170&message.id=75505&requireLogin=False

There is a VI attached to that forum post and within it they use a coherence function with the two inputs your looking for.

Let me know if this doesn't resolve your issue and I'll try to find more information for you.

Regards,
Matt S.