pistonrings               package:qcc               R Documentation

_P_i_s_t_o_n _r_i_n_g_s _d_a_t_a

_D_e_s_c_r_i_p_t_i_o_n:

     Piston rings for an automotive engine are produced by a forging
     process. The inside diameter of the rings manufactured by the
     process is measured on 25 samples, each of size 5, drawn from a
     process being considered `in control'.

_U_s_a_g_e:

     data(pistonrings)

_F_o_r_m_a_t:

     A data frame with 200 observations on the following 3 variables.

     _d_i_a_m_e_t_e_r a numeric vector

     _s_a_m_p_l_e sample ID

     _t_r_i_a_l trial sample indicator (TRUE/FALSE)

_R_e_f_e_r_e_n_c_e_s:

     Montgomery, D.C. (1991) _Introduction to Statistical Quality
     Control_, 2nd ed, New York, John Wiley & Sons, pp. 206-213

_E_x_a_m_p_l_e_s:

     data(pistonrings)
     attach(pistonrings)
     summary(pistonrings)
     boxplot(diameter ~ sample)
     plot(sample, diameter, cex=0.7)
     lines(tapply(diameter,sample,mean))
     detach(pistonrings)

