cband                 package:mixreg                 R Documentation

_C_a_l_c_u_l_a_t_e _c_o_n_f_i_d_e_n_c_e _a_n_d _p_r_e_d_i_c_t_i_o_n _b_a_n_d_s _f_o_r _m_i_x_t_u_r_e_s _o_f _o_n_e-_v_a_r_i_a_b_l_e
_r_e_g_r_e_s_s_i_o_n_s.

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

     Produces confidence and prediction bands, two-sided or upper or
     lower, for the lines fitted in a model consisting of a mixture of
     one-variable regressions.

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

     cband(object, cov.mat, x, y, alpha=0.05, xlen=100, plotit=FALSE,
           type=NULL)

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

  object: Object describing the fitted mixture of regressions, as
          returned by mixreg. 

 cov.mat: The estimated covariance matrix of the parameter estimates of
          the fit, as returned by covmix. 

       x: The vector of predictors for each of the regression models in
          the mixture.  Only one-dimensional predictors are permitted
          here. 

       y: The vector of responses for the regression models. 

   alpha: One minus the confidence level for the confidence and
          prediction bands; e.g. alpha = 0.05 for 95% confidence. 

    xlen: The number of points to be plotted in the band envelopes. 
          The x-values of the points will be equi-spaced from min(x) to
          max(x). 

  plotit: Logical argument indicating whether to plot the fitted model
          and confidence bands. 

    type: Character argument specifying the type of band.  Must have
          one of the values "both", "upper", or "lower".  Defaults to
          "both". 

_D_e_t_a_i_l_s:

     The prediction bands are conditional in that the associated
     probability is condtional upon the associated observation being
     generated by the relevant component of the mixture.

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

     A list (of class "cband") with components

   theta: The parameter list from object (as returned by mixreg). 

intercept: The logical value from object indicating whether intercepts
          were fitted. 

       x: The argument x of the call to cband. 

       y: The argument y of the call to cband. 

      xf: The equispaced sequence of values from min(x) to max(x) at
          which the values of the band envelopes were calculated. 

    bnds: A list with one entry for each component of the mixture. 
          Each entry is a matrix with 4 columns (lower and upper
          confidence, lower and upper prediction bounds) if type is
          "both", or with 2 columns (confidence bounds, prediction
          bounds) if type is "upper" or "lower". 

_S_i_d_e _E_f_f_e_c_t_s:

     If plotit is TRUE a plot of the fit and the confidence and
     prediction bands is produced in whatever device is currently open.

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

     Turner, T. R.  (2000) Estimating the rate of spread of a viral
     infection of potato plants via mixtures of regressions.  Appl.
     Statist. vol. 49, Part 3, pp. 371 - 384.

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

     bootcomp, covmix, mixreg, plot.cband, plot.mresid, qq.mix,
     resid.mix

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

     #See mixreg for examples.

