

amis(boot)                                   R Documentation

_C_a_r _S_p_e_e_d_i_n_g _a_n_d _W_a_r_n_i_n_g _S_i_g_n_s_.

_A_r_g_u_m_e_n_t_s_:

   speed: Speeds of cars (in miles per hour).

  period: A numeric column indicating the time that the
          reading was taken.  A value of 1 indicates a read-
          ing taken before the sign was erected, a 2 indi-
          cates a reading taken shortly after erection of
          the sign and a 3 indicates a reading taken after
          the sign had been in place for some time.

 warning: A numeric column indicating whether the location
          of the reading was chosen to have a warning sign
          erected. A value of 1 indicates presence of a sign
          and a value of 2 indicates that no sign was
          erected.

    pair: A numeric column giving the pair number at which
          the reading was taken. Pairs were numbered from 1
          to 14.

_S_U_M_M_A_R_Y_:

     The `amis' data frame has 8437 rows and 4 columns.

     In a study into the effect that warning signs have on
     speeding patterns, Cambridgeshire County Council con-
     sidered 14 pairs of locations.  The locations were
     paired to account for factors such as traffic volume
     and type of road.  One site in each pair had a sign
     erected warning of the dangers of speeding and asking
     drivers to slow down.  No action was taken at the sec-
     ond site.  Three sets of measurements were taken at
     each site.  Each set of measurements was nominally of
     the speeds of 100 cars but not all sites have exactly
     100 measurements. These speed measurements were taken
     before the erection of the sign, shortly after the
     erection of the sign, and again after the sign had been
     in place for some time.

_D_A_T_A _D_E_S_C_R_I_P_T_I_O_N_:

     This data frame contains the following columns:

_S_O_U_R_C_E_:

     The data were kindly made available by Mr. Graham Amis,
     Cambridgeshire County Council, U.K.

_O_T_H_E_R _R_E_F_E_R_E_N_C_E_S_:

     Davison, A.C. and Hinkley, D.V. (1997) Bootstrap Meth-
     ods and Their Application. Cambridge University Press.

