qreference               package:DAAG               R Documentation

_N_o_r_m_a_l _Q_Q _R_e_f_e_r_e_n_c_e _P_l_o_t

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

     This function computes the normal QQ plot for given data and
     allows for comparison with normal QQ plots of simulated data.

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

     qreference(test = NULL, m = 50, nrep = 6, distribution = function(x) qnorm(x, 
         mean = ifelse(is.null(test), 0, mean(test)), sd = ifelse(is.null(test), 
         1, sd(test))), seed = NULL, nrows = NULL, cex.strip = 0.75, 
         xlab = NULL, ylab = NULL) 

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

    test: a vector containing a sample to be tested; if not supplied,
          all qq-plots are of the reference distribution

       m: the sample size for the reference samples; default is test
          sample size if test sample is supplied

    nrep: the total number of samples, including reference samples and
          test sample if any

distribution: reference distribution; default is standard normal

    seed: the random number generator seed

   nrows: number of rows in the plot layout

cex.strip: character expansion factor for labels

    xlab: label for x-axis

    ylab: label for y-axis

_V_a_l_u_e:

     QQ plots of the sample (if test is non-null) and all reference
     samples

_A_u_t_h_o_r(_s):

     J.H. Maindonald

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

     # qreference(rt(180,1))

     # qreference(rt(180,1), distribution=function(x) qt(x, df=1))

     # qreference(rexp(180), nrep = 4)

     # toycars.lm <- lm(distance ~ angle + factor(car), data = toycars)
     # qreference(residuals(toycars.lm), nrep = 9)

