Right, you can calculate the coherence between any input and any output and if there is more than one input then that would partial. For the multiple coherence, it is the coherence between one output and all of it's inputs.
Also, does the coherence necessarily need to be real? I'm not sure...
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...
I've written all of these in Python. The exact implementation of the un-vec is:
alpha[:,0:1] = alpha[:,0:1] + delta_a[::2]
alpha[:,1:2] = alpha[:,1:2] + delta_a[1::2]
the colon's inside the array dimensions are start:stop:step. The delta_a array is the vec'd array, so the length is twice as...
I think there are multiple errors in the paper "a poly reference implementation of the maximum likelihood complex frequency domain estimator and some industrial applicatinos.pdf"
I have programmed up the LSCF, MLFD, and p-LSCF methods and am having trouble with the final piece p-MLFD. The...
Thanks Greg,
You can construct the stability diagram by summing all outputs over all references. Or, you can sum over all outputs grouped by all references.
For example the former (sum over all outputs over all references):
The upper limit of the sum is NoNi (# of outputs, # of references)...
Hello Everyone,
When using the poly-reference least squares complex frequency domain estimator (p-LSCF) to estimate modal parameters, you iteratively increase the model order and plot successive pole estimates on a stability diagram. In the literature it says you can only increase the model...
Hello Everyone,
When using the poly-reference least squares complex frequency domain estimator (p-LSCF) to estimate modal parameters, you iteratively increase the model order and plot successive pole estimates on a stability diagram. In the literature it says you can only increase the model...
Hi
I've ran a random vibration analysis (sol 111) and I have made an element stress punch file (ELSTRESS(SORT2,PUNCH,REAL)), but when I open the file I don't know how to read it. I see the grid Id and the frequency but the rest of the numbers I don't know what they are. Does anyone know of a...
