bsquare.m

A 2D homogeneous Helmholtz case (u=sin(x)cos(y) with a square) with ％ two Dirichlet edges (x=1,y=1

% Uniform boundary node data set for a sqaure domain [0,a]*[0,b]
% Rx is a set of coordinates along x-axe
% Ry is a set of coordinates along y-axe


function [Rx,Ry]=Bsquare(a,b,n)

  Rx=zeros(4*n-4); % preallocating memory
  Ry=zeros(4*n-4);  

% edge x=a, y=[0,b]
for j=1:n
    Rx(j)=a;  
    Ry(j)=(j-1)*b/(n-1);
end
m=n;

% edge x=[a,0], y=b
for i=2:n
    Rx(m+i-1)=a-(i-1)*a/(n-1);  
    Ry(m+i-1)=b;
end
m=m+n-1;

% edge x=0, y=[b,0]
for j=2:n
    Rx(m+j-1)=0;  
    Ry(m+j-1)=b-(j-1)*b/(n-1);
end
m=m+n-1;

% edge x=[0,a], y=0
for i=2:n-1
    Rx(m+i-1)=(i-1)*a/(n-1);  
    Ry(m+i-1)=0;
end
m=m+n-2;