rlplot               package:extRemes               R Documentation

_C_r_e_a_t_e _a _r_e_t_u_r_n _l_e_v_e_l _p_l_o_t _f_o_r _a _f_i_t_t_e_d _o_b_j_e_c_t _o_f _a_n _e_x_t_r_e_m_e-_v_a_l_u_e _d_i_s_t_r_i_b_u_t_i_o_n.

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

     Plots several return levels against the return period for a fitted
     object from one of the 'ismev' functions: 'gev.fit' and 'gpd.fit'.

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

     rlplot(z, ci = 0.05, add.ci = FALSE)

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

       z: A list object as returned by one of gev.fit or gpd.fit (with
          appropriate class attribute added). 

      ci: The (1-ci)*100 confidence value.

  add.ci: logical if true will add confidence bounds to plot.

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

     Given a fitted list object from 'gev.fit' or 'gpd.fit'-attributed
     with the class "gev.fit" or "gpd.fit", respectively-the return
     level plot is generated.  Confidence bounds, if included, are
     found by the delta method, which is generally appropriate for
     shorter return periods, but not for longer return periods because
     the return level distribution is generally skewed.  Therefore, if
     a plot with better estimates of the confidence bounds are desired,
     use 'add.ci=FALSE', and use the R function 'lines' to add
     different bounds (e.g., using values obtained from the
     'gev.parameterCI' or 'gpd.parameterCI' functions).

     This function is simply a modification of Stuart Coles' functions
     'gpd.rl' and 'gev.rl' (Coles, 2001).

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

     A plot is created.  If assigned to an object, a list will be
     returned with the following items. 

  period: The return periods used for calculating the return levels.

   level: The estimated return level for each return period.

   lower: If add.ci is TRUE, then this is a vector of lower 1-ci
          confidence bounds.  Otherwise the value is NULL.

   upper: If add.ci is TRUE, then this is a vector of upper 1-ci
          confidence bounds.  Otherwise the value is NULL.

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

     Eric Gilleland

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

     Coles, Stuart.  "An introduction to statistical modeling of
     extreme values", Springer-Verlag (London), 2001.

     Gilleland, Eric and Katz, Richard W. Tutorial for the 'Extremes
     Toolkit: Weather and Climate Applications of Extreme Value
     Statistics.' <URL: http://www.assessment.ucar.edu/toolkit>, 2005.

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

     'gev.parameterCI', 'gpd.parameterCI', 'gev.diag', 'gpd.diag'

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

     data(ftcanmax)
     fit <- gev.fit( ftcanmax[,"Prec"])
     class( fit) <- "gev.fit"
     rlplot( fit)

