Babel function

The Babel function (also known as cumulative coherence) measures the maximum total coherence between a fixed atom and a collection of other atoms in a dictionary. The Babel function was conceived of in the context of signals for which there exists a sparse representation consisting of atoms or columns of a redundant dictionary matrix, A.

Definition and formulation

The Babel function of a dictionary with normalized columns is a real-valued function that is defined as

where are the columns (atoms) of the dictionary .[1][2]

Special case

When p=1, the babel function is the mutual coherence.

Pratical Applications

Li and Lin have used the Babel function to aid in creating effective dictionaries for Machine Learning applications.[3]

References

See also

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