function r8bb_print_some ( n1, n2, ml, mu, a, ilo, jlo, ihi, jhi, title )

%*****************************************************************************80
%
%% R8BB_PRINT_SOME prints some of a R8BB matrix.
%
%  Discussion:
%
%    The R8BB storage format is for a border banded matrix.  Such a
%    matrix has the logical form:
%
%      A1 | A2
%      ---+---
%      A3 | A4
%
%    with A1 a (usually large) N1 by N1 banded matrix, while A2, A3 and A4
%    are dense rectangular matrices of orders N1 by N2, N2 by N1, and N2 by N2,
%    respectively.
%
%    A should be defined as a vector.  The user must then store
%    the entries of the four blocks of the matrix into the vector A.
%    Each block is stored by columns.
%
%    A1, the banded portion of the matrix, is stored in
%    the first (2*ML+MU+1)*N1 entries of A, using standard LINPACK
%    general band format.  The reason for the factor of 2 in front of
%    ML is to allocate space that may be required if pivoting occurs.
%
%    The following formulas should be used to determine how to store
%    the entry corresponding to row I and column J in the original matrix:
%
%    Entries of A1:
%
%      1 <= I <= N1, 1 <= J <= N1, (J-I) <= MU and (I-J) <= ML.
%
%      Store the I, J entry into location
%      (I-J+ML+MU+1)+(J-1)*(2*ML+MU+1).
%
%    Entries of A2:
%
%      1 <= I <= N1, N1+1 <= J <= N1+N2.
%
%      Store the I, J entry into location
%      (2*ML+MU+1)*N1+(J-N1-1)*N1+I.
%
%    Entries of A3:
%
%      N1+1 <= I <= N1+N2, 1 <= J <= n1.
%
%      Store the I, J entry into location
%      (2*ML+MU+1)*N1+N1*N2+(J-1)*N2+(I-N1).
%
%    Entries of A4:
%
%      N1+1 <= I <= N1+N2, N1+1 <= J <= N1+N2
%
%      Store the I, J entry into location
%      (2*ML+MU+1)*N1+N1*N2+(J-1)*N2+(I-N1).
%      (same formula used for A3).
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    07 April 2006
%
%  Author:
%
%    John Burkardt
%
%  Parameters:
%
%    Input, integer N1, N2, the order of the banded and dense blocks.
%    N1 and N2 must be nonnegative, and at least one must be positive.
%
%    Input, integer ML, MU, the lower and upper bandwidths.
%    ML and MU must be nonnegative, and no greater than N1-1.
%
%    Input, real A((2*ML+MU+1)*N1+2*N1*N2+N2*N2), the R8BB matrix.
%
%    Input, integer ILO, JLO, IHI, JHI, the first row and
%    column, and the last row and column to be printed.
%
%    Input, string TITLE, a title.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '%s\n', title );

  incx = 5;
%
%  Print the columns of the matrix, in strips of 5.
%
  for j2lo = jlo : incx : jhi

    j2hi = j2lo + incx - 1;
    j2hi = min ( j2hi, n1+n2 );
    j2hi = min ( j2hi, jhi );

    inc = j2hi + 1 - j2lo;

    fprintf ( 1, '\n' );
    fprintf ( 1, '  Col: ' );

    for j = j2lo : j2hi
      fprintf ( 1, '%7d       ', j )
    end

    fprintf ( 1, '\n' );
    fprintf ( 1, '  Row\n' );
    fprintf ( 1, '  ---\n' );
%
%  Determine the range of the rows in this strip.
%
    i2lo = max ( ilo, 1 );
    i2hi = min ( ihi, n1+n2 );

    for i = i2lo : i2hi

      fprintf ( 1, '%4d  ', i );
%
%  Print out (up to) 5 entries in row I, that lie in the current strip.
%
      for j2 = 1 : inc

        j = j2lo - 1 + j2;

        aij = 0.0E+00;

        if ( i <= n1 & j <= n1 )
          if ( (j-i) <= mu+ml & (i-j) <= ml )
            ij = (i-j+ml+mu+1)+(j-1)*(2*ml+mu+1);
            aij = a(ij);
          end
        elseif ( i <= n1 & n1 < j )
          ij = (2*ml+mu+1)*n1+(j-n1-1)*n1+i;
          aij = a(ij);
        elseif ( n1 < i )
          ij = (2*ml+mu+1)*n1+n2*n1+(j-1)*n2+(i-n1);
          aij = a(ij);
        end

        fprintf ( 1, '%12g  ', aij );

      end

      fprintf ( 1, '\n' );

    end

  end

  fprintf ( 1, '\n' );

  return
end
