quawak {lmomco}R Documentation

Quantile Function of the Wakeby Distribution

Description

This function computes the quantiles of the Wakeby distribution given parameters (xi, α, β, gamma, and delta) of the distribution computed by parwak. The quantile function of the distribution is

x(F) = xi+frac{α}{β}(1-(1-F)^β)- frac{gamma}{delta}(1-(1-F))^{-delta} mbox{,}

where x(F) is the quantile for nonexceedance probability F, xi is a location parameter, α and β are scale parameters, and gamma, and delta are shape parameters. The five returned parameters from parwak in order are xi, α, β, gamma, and delta.

Usage

quawak(f, wakpara)

Arguments

f Nonexceedance probability (0 <= F <= 1).
wakpara The parameters from parwak or similar.

Value

Quantile value for nonexceedance probability F.

Author(s)

W.H. Asquith

References

Hosking, J.R.M., 1990, L-moments—Analysis and estimation of distributions using linear combinations of order statistics: Journal of the Royal Statistical Society, Series B, vol. 52, p. 105–124.

Hosking, J.R.M., 1996, FORTRAN routines for use with the method of L-moments: Version 3, IBM Research Report RC20525, T.J. Watson Research Center, Yorktown Heights, New York.

Hosking, J.R.M. and Wallis, J.R., 1997, Regional frequency analysis—An approach based on L-moments: Cambridge University Press.

See Also

cdfwak, parwak

Examples

  lmr <- lmom.ub(c(123,34,4,654,37,78))
  quawak(0.5,parwak(lmr))

[Package lmomco version 0.96.3 Index]