function [p, Info] = amd2 (A, Control)					    %#ok
  %AMD2 p = amd2 (A), the approximate minimum degree ordering of A
  %    P = AMD2 (S) returns the approximate minimum degree permutation vector for
  %    the sparse matrix C = S+S'.  The Cholesky factorization of C (P,P), or
  %    S (P,P), tends to be sparser than that of C or S.  AMD tends to be faster
  %    than SYMMMD and SYMAMD, and tends to return better orderings than SYMMMD.
  %    S must be square. If S is full, amd(S) is equivalent to amd(sparse(S)).
  %
  %    Note that the built-in AMD routine in MATLAB is identical to AMD2,
  %    except that AMD in MATLAB allows for a struct input to set the parameters.
  %
  %    Usage:  P = amd2 (S) ;                  % finds the ordering
  %            [P, Info] = amd2 (S, Control) ; % optional parameters & statistics
  %            Control = amd2 ;                % returns default parameters
  %            amd2 ;                          % prints default parameters.
  %
  %       Control (1); If S is n-by-n, then rows/columns with more than
  %           max (16, (Control (1))* sqrt(n)) entries in S+S' are considered
  %           "dense", and ignored during ordering.  They are placed last in the
  %           output permutation.  The default is 10.0 if Control is not present.
  %       Control (2): If nonzero, then aggressive absorption is performed.
  %           This is the default if Control is not present.
  %       Control (3): If nonzero, print statistics about the ordering.
  %
  %       Info (1): status (0: ok, -1: out of memory, -2: matrix invalid)
  %       Info (2): n = size (A,1)
  %       Info (3): nnz (A)
  %       Info (4): the symmetry of the matrix S (0.0 means purely unsymmetric,
  %           1.0 means purely symmetric).  Computed as:
  %           B = tril (S, -1) + triu (S, 1) ; symmetry = nnz (B & B') / nnz (B);
  %       Info (5): nnz (diag (S))
  %       Info (6): nnz in S+S', excluding the diagonal (= nnz (B+B'))
  %       Info (7): number "dense" rows/columns in S+S'
  %       Info (8): the amount of memory used by AMD, in bytes
  %       Info (9): the number of memory compactions performed by AMD
  %
  %    The following statistics are slight upper bounds because of the
  %    approximate degree in AMD.  The bounds are looser if "dense" rows/columns
  %    are ignored during ordering (Info (7) > 0).  The statistics are for a
  %    subsequent factorization of the matrix C (P,P).  The LU factorization
  %    statistics assume no pivoting.
  %
  %       Info (10): the number of nonzeros in L, excluding the diagonal
  %       Info (11): the number of divide operations for LL', LDL', or LU
  %       Info (12): the number of multiply-subtract pairs for LL' or LDL'
  %       Info (13): the number of multiply-subtract pairs for LU
  %       Info (14): the max # of nonzeros in any column of L (incl. diagonal)
  %       Info (15:20): unused, reserved for future use
  %
  %    An assembly tree post-ordering is performed, which is typically the same
  %    as an elimination tree post-ordering.  It is not always identical because
  %    of the approximate degree update used, and because "dense" rows/columns
  %    do not take part in the post-order.  It well-suited for a subsequent
  %    "chol", however.  If you require a precise elimination tree post-ordering,
  %    then see the example below:
  %
  % Example:
  %
  %       P = amd2 (S) ;
  %       C = spones (S) + spones (S') ;  % skip this if S already symmetric
  %       [ignore, Q] = etree (C (P,P)) ;
  %       P = P (Q) ;
  %
  % See also AMD, COLMMD, COLAMD, COLPERM, SYMAMD, SYMMMD, SYMRCM.
  
  % --------------------------------------------------------------------------
  % Copyright 1994-2007, Tim Davis, University of Florida
  % Patrick R. Amestoy, and Iain S. Duff.  See ../README.txt for License.
  % email: davis at cise.ufl.edu    CISE Department, Univ. of Florida.
  % web: http://www.cise.ufl.edu/research/sparse/amd
  % --------------------------------------------------------------------------
  %
  %    Acknowledgements: This work was supported by the National Science
  %       Foundation, under grants ASC-9111263, DMS-9223088, and CCR-0203270.
  
  error ('amd2 mexFunction not found') ;