laplace

LAPLACE Construct a simple d-dimensional Laplace operator and return TTeMPS_op_laplace object.

0001 %LAPLACE Construct a simple d-dimensional Laplace operator and return TTeMPS_op_laplace object.
0002 
0003 %   TTeMPS Toolbox.
0004 %   Michael Steinlechner, 2013-2016
0005 %   Questions and contact: michael.steinlechner@epfl.ch
0006 %   BSD 2-clause license, see LICENSE.txt
0007 
0008 function L = laplace( I, n, d );
0009 
0010     one = ones(n,1);
0011     q = linspace( I(1), I(2), n)';
0012     h = abs(q(2) - q(1));
0013     L0 = -spdiags( [one, -2*one, one], [-1 0 1], n, n) / (h^2);
0014     
0015     L = TTeMPS_op_laplace( L0, d );
0016 end