function p=pu(mh,mv,border)
% PU creates the coarse mesh basis
%
% function p=pu(mh,mv,border)
%
p=zeros(mh,mv);
hl=border+1; hu=mh-border; 
vl=border+1; vu=mv-border;
dh=(border+1); dv=(border+1);
bx=border;
px=pu1d(mh,border); py=pu1d(mv,border);
p=px*py';
%
% the basis in 1D
%
function p=pu1d(mh,overlap)
del=overlap;
p=ones(mh,1);
x=1:mh; h=1/(mh+1); x=x'*h;
if 2*del > mh
	del = floor(mh/2);
end
mr=del; ml=mh-del-1;
xr=0; xl=(ml+1)*h;
for i=1:del+1
	p(i)=(x(i)-xr)/(x(del+1)-xr);
end
for i=ml+1:mh
	p(i)=(1-x(i))/(1-x(ml+1));
end