plot "./ex3.dat" using 0:1 title "fi" w l, "./ex3.dat" using 0:3 title "psi" w l,"./ex3.dat" using 0:5 title "theta" w l,"./ex2.dat" using 0:1 title "fi2", "./ex2.dat" using 0:3 title "psi2" w l,"./ex2.dat" using 0:5 title "theta2" w l