startberngamma: Rough parameter estimate for the Bernoulli-Gamma distribution

In qmap: Statistical Transformations for Post-Processing Climate Model Output

Description

Estimates rough starting values for the Bernoulli-Gamma distribution using the method of moments for the shape and the scale parameters. The probability of non-zero events is estimated as the fraction of values that are larger than zero.

Usage

startberngamma(x)

Arguments

x	numeric vector.

Value

A list containing:

prob	probability of non-zero event.
scale	scale parameter of the gamma distribution.
shape	shape parameter of the gamma distribution.

Note

In this package startberngamma is intended to be used in conjunction with fitQmapDIST (and mledist) with parameter distr="berngamma".

Author(s)

Lukas Gudmundsson

See Also

fitQmapDIST, berngamma, fitdist

Examples

gg <- rberngamma(n=300, prob=0.2, scale=1, shape=1)
startberngamma(gg)
mledist(gg,"berngamma",startberngamma(gg))

Example output

Loading required package: fitdistrplus
Loading required package: MASS
Loading required package: survival
Loading required package: npsurv
Loading required package: lsei
$prob
[1] 0.1466667

$scale
[1] 0.5938249

$shape
[1] 1.914762

$estimate
     prob     scale     shape 
0.1466519 0.9589830 1.1855849 

$convergence
[1] 0

$value
[1] 174.3349

$hessian
          prob    scale    shape
prob  2397.609  0.00000  0.00000
scale    0.000 56.73167 45.88196
shape    0.000 45.88196 56.71718

$optim.function
[1] "optim"

$optim.method
[1] "Nelder-Mead"

$fix.arg
NULL

$fix.arg.fun
NULL

$weights
NULL

$counts
function gradient 
     202       NA 

$optim.message
NULL

$loglik
[1] -174.3349

qmap documentation built on May 1, 2019, 7:31 p.m.