It's not really clear, but here's a guess
% two unequal length vectors
x = 1:5;
y = 1:6;
% assuming the vectors imply a uniform rectangular mesh
[xx yy] = meshgrid(x,y);
% is the "data" just a linear series?
data = linspace(1,300,30);
scatter(xx(:),yy(:),[],data,'filled')
colorbar
colormap jet
xlabel('x')
ylabel('y')
