means                  package:Rlab                  R Documentation

_C_o_m_p_u_t_e_s _o_n_e-_w_a_y _a_n_d _t_w_o-_w_a_y _m_e_a_n_s _t_a_b_l_e_s

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

     Calculates means for individual factors and two-way factor
     combinations. Any number of factors may be input and the indivdual
     factor means as well as all possible two-way means will be shown
     for each factor.  Three-way, four-way, etc. means are not shown,
     even when more than 2 factors are given.

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

     means(y, ..., dec = 3)

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

       y: Vector of responses whose means are shown. 

     ...: Vectors of independent variables on which the responses'
          means are broken down. 

     dec: Number of decimal places to print. 

_S_e_e _A_l_s_o:

     mplot, mean

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

     # Create a data set with two factors (age and gender)
     race<-data.frame(c(1.02,.99,1.11,1.30,1.09,1.26,1.21,1.19,1.30,1.45,1.34,1.49),
                      c('M','M','M','M','M','M','F','F','F','F','F','F'),
                      c('under 50','under 50','under 50','over 50','over 50','over 50',
                        'under 50','under 50','under 50','over 50','over 50','over 50'))
     names(race)<-c("time","gender","age")

     # Show mean times broken by age, gender and age & gender
     means(race$time, race$age, race$gender)

