frechet                 package:evd                 R Documentation

_T_h_e _F_r_e_c_h_e_t _D_i_s_t_r_i_b_u_t_i_o_n

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

     Density function, distribution function, quantile function and
     random generation for the Frechet distribution with location,
     scale and shape parameters.

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

     dfrechet(x, loc=0, scale=1, shape=1, log = FALSE) 
     pfrechet(q, loc=0, scale=1, shape=1, lower.tail = TRUE) 
     qfrechet(p, loc=0, scale=1, shape=1, lower.tail = TRUE)
     rfrechet(n, loc=0, scale=1, shape=1)

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

    x, q: Vector of quantiles.

       p: Vector of probabilities.

       n: Number of observations.

loc, scale, shape: Location, scale and shape parameters (can be given
          as vectors).

     log: Logical; if 'TRUE', the log density is returned.

lower.tail: Logical; if 'TRUE' (default), probabilities are P[X <= x],
          otherwise, P[X > x]

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

     The Frechet distribution function with parameters 'loc' = a,
     'scale' = b and 'shape' = s is

                     G(x) = exp{-[(z-a)/b]^(-s)}

     for z > a and zero otherwise, where b > 0 and s > 0.

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

     'dfrechet' gives the density function, 'pfrechet' gives the
     distribution function, 'qfrechet' gives the quantile function, and
     'rfrechet' generates random deviates.

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

     'rgev', 'rgumbel', 'rrweibull'

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

     dfrechet(2:4, 1, 0.5, 0.8)
     pfrechet(2:4, 1, 0.5, 0.8)
     qfrechet(seq(0.9, 0.6, -0.1), 2, 0.5, 0.8)
     rfrechet(6, 1, 0.5, 0.8)
     p <- (1:9)/10
     pfrechet(qfrechet(p, 1, 2, 0.8), 1, 2, 0.8)
     ## [1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

