SHRINKAGE Network shrinkage

   X1 = shrinkage(X)

   Inputs:
       X:  Network matrix of size n x n

   Outputs:
       X1: Shrunken network matrix.

   Methodological notes:
       The shrinkage algorithm uses cubic interpolation to "despike" an
       initial peak in the eigenspectrum.

   See also:
       RESIDUALN.