divNonUniform

 Returns a m+2 by m+1 one-dimensional non-uniform mimetic divergence
 operator

 Parameters:
                k : Order of accuracy
                ticks : Edges' ticks e.g. [0 0.1 0.15 0.2 0.3 0.4 0.45]
 ----------------------------------------------------------------------------
 SPDX-License-Identifier: GPL-3.0-or-later
 © 2008-2024 San Diego State University Research Foundation (SDSURF).
 See LICENSE file or https://www.gnu.org/licenses/gpl-3.0.html for details.
 ----------------------------------------------------------------------------

0001 function D = divNonUniform(k, ticks)
0002 % Returns a m+2 by m+1 one-dimensional non-uniform mimetic divergence
0003 % operator
0004 %
0005 % Parameters:
0006 %                k : Order of accuracy
0007 %                ticks : Edges' ticks e.g. [0 0.1 0.15 0.2 0.3 0.4 0.45]
0008 % ----------------------------------------------------------------------------
0009 % SPDX-License-Identifier: GPL-3.0-or-later
0010 % © 2008-2024 San Diego State University Research Foundation (SDSURF).
0011 % See LICENSE file or https://www.gnu.org/licenses/gpl-3.0.html for details.
0012 % ----------------------------------------------------------------------------
0013 
0014     % Get uniform operator without scaling
0015     D = div(k, length(ticks)-1, 1);
0016     
0017     [m, ~] = size(D);
0018     
0019     % Compute the Jacobian using the uniform operator and the ticks
0020     if size(ticks, 1) == 1
0021         J = spdiags((D*ticks').^-1, 0, m, m);
0022     else
0023         J = spdiags((D*ticks).^-1, 0, m, m);
0024     end
0025     
0026     % This is the non-uniform operator
0027     D = J*D;
0028 end