% **************************************************************
% lbem2 : Sets up matrices for BEM for Laplace's Equation
% **************************************************************
% BEM-LAP-MAT project
% Matlab/Freemat codes
% Copyright 2008- Stephen Kirkup
% John Tyndall Nuclear Research Institute
% School of Computing Engineering and Physical Sciences
% University of Central Lancashire - www.uclan.ac.uk 
% Westlakes Campus
% Samuel Lindow Building
% West Lakes Science and Technology Park
% Whitehaven
% Cumbria CA24 3JY
% United Kingdom
% smkirkup@uclan.ac.uk
%
% This open source code can be found at
% boundary-element-method.com/freematlab/lbem2.m
%
%  Issued under the GNU General Public License 2007, see gpl.txt
%
%  Part of the the author's open source BEM packages. 
%  All codes and manuals can be downloaded from 
%  www.boundary-element-method.com
%
% **************************************************************

% function [L,M,Mt,N] = lbem2(m,p,vecp,n,vertpts,elemvert,p_on,needL,needM,needMt,needN)
% Sets up the matrices required in the boundary element method
%  for m (observation) points p with a vector (derivative) direction of
%  vecp at the points p. The boundary is made up of n elements; vertpts lists the coordinates
%  of the edges of the elements and elemvert lists the pairs of vertices
%  that define each element. p_on idicates whether the point p(i) lies on the ith panel.
%  needL,needM,needMt,needN indicate which matrices are needed by being set to true.


function [L,M,Mt,N] =lbem2(m,p,vecp,n,vertpts,elemvert,p_on,needL,needM,needMt,needN)
  
  [qa,qb]=vertices(n,vertpts,elemvert);

  for (i=1:m)
    for (j=1:n)
    [L(i,j),M(i,j),Mt(i,j),N(i,j)]=l2lc(p(i,:),vecp(i,:),qa(j,:),qb(j,:),p_on&i==j,needL,needM,needMt,needN);
    end
  end