Bicoherence: Difference between revisions

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The normalization is such that 0 &le; ''b<sup>2</sup>'' &le; 1.
The normalization is such that 0 &le; ''b<sup>2</sup>'' &le; 1.


The bicoherence is symmetric under the symmetries ''(&omega;<sub>1</sub>,&omega;<sub>2</sub>) &rarr; (&omega;<sub>2</sub>,&omega;<sub>1</sub>)'' and  
The bicoherence is symmetric under the transformations ''(&omega;<sub>1</sub>,&omega;<sub>2</sub>) &rarr; (&omega;<sub>2</sub>,&omega;<sub>1</sub>)'' and  
''(&omega;<sub>1</sub>,&omega;<sub>2</sub>) &rarr; (-&omega;<sub>1</sub>,-&omega;<sub>2</sub>)'', so that only one quarter of the plane ''(&omega;<sub>1</sub>,&omega;<sub>2</sub>)'' contains independent information.
''(&omega;<sub>1</sub>,&omega;<sub>2</sub>) &rarr; (-&omega;<sub>1</sub>,-&omega;<sub>2</sub>)'', so that only one quarter of the plane ''(&omega;<sub>1</sub>,&omega;<sub>2</sub>)'' contains independent information.
Additionally, for discretely sampled data all frequencies must be less than the  
Additionally, for discretely sampled data all frequencies must be less than the  
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The summed bicoherence is defined by
The summed bicoherence is defined by


:<math>\frac{1}{N} \sum_{\omega_1+\omega_2=\omega}{b^2(\omega_1,\omega_2)} </math>
:<math>\frac{1}{N(\omega)} \sum_{\omega_1+\omega_2=\omega}{b^2(\omega_1,\omega_2)} </math>


where ''N'' is the number of terms in the sum.  
where ''N'' is the number of terms in the sum.