This function is not yet fully documented. This is a transcript of the text-formatted help.

bbhankel  Create a black-box operator for a Hankel matrix.
  BB=bbhankel(C,R) creates a black-box operator corresponding
  to a Hankel-matrix whose first column is C and last row R.
  The least element of C must be the same as the first
  element of R.

  BB=bbhankel(C) is the square Hankel-matrix produced when R
  is zero, except for the first element.

  See also bbtoeplitz, .