multiple coherence function
multiple coherence function
(OP)
The multiple coherence function can be defined by:

These values are FRF auto/cross powers in my context. Multiple coherence means there are multiple inputs. For 2 inputs the dimensions of Pxy is 2x1, Pxx is 2x2, Pyy is 1x1. I'm expecting the plot to be mostly 1 with dips at the FRF anti-resonances.
Should this also be between 0 and 1? Are the values (Px, Pxx, Pyy) the averaged values?
Thanks,

These values are FRF auto/cross powers in my context. Multiple coherence means there are multiple inputs. For 2 inputs the dimensions of Pxy is 2x1, Pxx is 2x2, Pyy is 1x1. I'm expecting the plot to be mostly 1 with dips at the FRF anti-resonances.
Should this also be between 0 and 1? Are the values (Px, Pxx, Pyy) the averaged values?
Thanks,
RE: multiple coherence function
I'm very rusty on this, but yes, the total of the partial coherences should be 1 at each frequency in the absence of noise and non linearities. Px etc are your ensemble averages.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: multiple coherence function
Also, does the coherence necessarily need to be real? I'm not sure what a complex coherence would mean...
RE: multiple coherence function
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?