fv_l1l2_error.m

function l1l2_error = fv_l1l2_error(U1,U2,W,params)
%function l1l2_error = fv_l1l2_error(U1,U2,W,params)
%
% function computing the l1([0,T],l2)-error between the two
% fv-functions or function
% sequences in U1,U2. Result is a single value or sequence of values 
% corresponding to the column-differences between U1 and U2
% correct Omega-integrals are computed by respecting the cell-areas
% defined in grid,params. Params defines the time-spacing for
% correct time integration
%
% note, that the last snapshot does not contribute to the error,
% as FV functions are assumed to be piecewise constant on a forward 
% time-intervall.

% Bernard Haasdonk 7.11.2008
  
%  l2_error = sqrt(sum(((U1-U2).^2).*repmat(grid.A(:),1,size(U1,2))));
%A = sparse(1:size(U1,1),1:size(U1,1),grid.A(:));
linf_l2_error = sqrt(sum(W * ((U1-U2).^2)));
l1l2_error = cumsum(linf_l2_error * params.T/params.nt);
l1l2_error = [0,l1l2_error(1:end-1)];%| \docupdate