yv=[];
xv=[];
px=[];
for xi = 1:111
	x = (xi-6)/100;
	for yi = 1:111
		y = (yi-6)/100;
		xv(xi,yi) = x;
		yv(xi,yi) = y;
		px(xi,yi) = 0;
		if(x > 0)
			if(x < 1)
				if(y > 0)
					if(y < 1)
						px(xi, yi) = 2*y;
					end
				end
			end
		end
	end
end

surf(xv, yv, px);
shading('interp');