inner_product.m

function K = inner_product(U1,U2,grid,params)
%function K = inner_product(U1,U2,grid,params)
%
% function computing the l2 inner product between all pairs of 
% discrete functions in U1,U2. Result is a matrix K of size size(U1,2) x
% size(U2,2) with the inner products.
% Correct Omega-integrals are computed by respecting the cell-areas
%
% required fields of params:
%
%     'inner_product_matrix_algorithm' : name of function, which
%         gives the matrix W for L2-norm computation U1' * W * U2
%         e.g. fv_inner_product_matrix. Arguments of this function
%         are the grid and params.

% Bernard Haasdonk 20.7.2006

% currently simple diagonal weighting of element values sufficient
W = inner_product_matrix(grid,params);
K = U1' * W * U2;  

% TO BE ADJUSTED TO NEW SYNTAX
%| \docupdate