function nhba = bandwidth ( nnodes, element_num, element_node, node_num, indx )

%% BANDWIDTH determines the bandwidth of the coefficient matrix.
%
%  Modified:
%
%    05 April 2004
%
%  Parameters:
%
%    Input, integer NNODES, the number of local nodes per element.
%
%    Input, integer ELEMENT_NUM, the number of elements.
%
%    Input, integer ELEMENT_NODE(NNODES,ELEMENT_NUM);
%    ELEMENT_NODE(I,J) is the global index of local node I in element J.
%
%    Input, integer NODE_NUM, the number of nodes.
%
%    Input, integer INDX(NODE_NUM), the index of the unknown in the 
%    finite element linear system.
%
%    Output, integer NHBA, the half bandwidth of the matrix.
%
  nhba = 0;
  for element = 1 : element_num
    for iln = 1 : nnodes
      in = element_node(iln,element);
      i = indx(in);
      if ( 0 < i )
        for jln = 1 : nnodes
          jn = element_node(jln,element);
          j = indx(jn);
          nhba = max ( nhba, j - i );
        end
      end
    end
  end