% hold on;
nelx = 5;nely = 30;
[gx,gy]=meshgrid(0:max(nelx,nely));
plot(gx+0.5,gy+0.5,'k',gy+0.5,gx+0.5,'k','LineWidth',2);
axis tight; axis off;
axis([0 nelx+0.5 0 nely+0.5]);
%axis([0 nelx 0 nely]);
set(gcf,'color',[0.5,0.5,0.5]);%set background color = gray;