fitdistrplus (version 0.1-3)

mmedist: Fitting of univariate distributions by matching moments

Description

Fits a univariate distribution by matching moments.

Usage

mmedist(data, distr)

Arguments

data

A numeric vector.

distr

A character string "name" naming a distribution or directly the density function dname. The estimated values of the distribution parameters are provided only for the following distributions :

Value

• mmedist returns the named parameter or a named vector of parameters.

Details

For distributions characterized by one parameter ("geom", "pois" and "exp"), this parameter is simply estimated by matching theoretical and observed means, and for distributions characterized by two parameters, these parameters are estimated by matching theoretical and observed means and variances (Vose, 2000). This function is not intended to be called directly but is internally called in fitdist and bootdist when used with the matching moments method.

References

Vose D (2000) Risk analysis, a quantitative guide. John Wiley & Sons Ltd, Chischester, England, pp. 99-143. Evans M, Hastings N and Peacock B (2000) Statistical distributions. John Wiley and Sons Inc.

See Also

mledist, fitdist and bootdist.

Examples

x1<-c(6.4,13.3,4.1,1.3,14.1,10.6,9.9,9.6,15.3,22.1,13.4,
13.2,8.4,6.3,8.9,5.2,10.9,14.4)
mmedist(x1,"norm")

x2<-c(rep(4,1),rep(2,3),rep(1,7),rep(0,12))
mmedist(x2,"pois")

x3<-c(0.80,0.72,0.88,0.84,0.38,0.64,0.69,0.48,0.73,0.58,0.81,
0.83,0.71,0.75,0.59)
mmedist(x3,"beta")