N = 10 ;
x1 = rand(N,1) ; y1 = rand(N,1); z1 = rand(N,1) ;
x2 = rand(N,1) ; y2 = rand(N,1); z2 = rand(N,1) ;
x3 = rand(N,1) ; y3 = rand(N,1); z3 = rand(N,1) ;
figure
hold on
scatter3(x1,y1,z1,'MarkerEdgeColor','r','MarkerFaceColor',rand(1,3))
scatter3(x2,y2,z2,'MarkerEdgeColor','b','MarkerFaceColor',rand(1,3))
scatter3(x3,y3,z3,'MarkerEdgeColor','g','MarkerFaceColor',rand(1,3))
legend([{'First'},{'Second'},{'Third'}])
