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Last data update: 2014.03.03

R: Estimation of parameters of the Gamma distribution

gammafit

R Documentation

Estimation of parameters of the Gamma distribution

Description

Likelihood estimation of parameters of the Gamma distribution. Data can be right censored.

Usage

gammafit(time, event)

Arguments

`time`	numeric vector. For right censored data, this is the follow up time.
`event`	status indicator vector, 0=alive, 1=dead.

Value

A list with the following components:

`par`	best estimate of parameter vector `c(shape, scale)`
`value`	value of the likelihood at termination.
`feval`	number of times the likelihood was evaluated.
`restarts`	number of times the algorithm had to be restarted when it stagnated.
`convergence`	an integer code indicating type of convergence. 0 indicates successful convergence. Positive integer codes indicate failure to converge.
`message`	a text message indicating the type of convergence or failure.

Author(s)

Josef Brejcha

Examples

n <- 30
t <- rgamma(n, shape=2, scale=100)
ev <- round(runif(n), 0)
gammafit(t, ev)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(BivarP)
Loading required package: dfoptim
Loading required package: survival
Loading required package: copula
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/BivarP/gammafit.Rd_%03d_medium.png", width=480, height=480)
> ### Name: gammafit
> ### Title: Estimation of parameters of the Gamma distribution
> ### Aliases: gammafit
> ### Keywords: ~kwd1 ~kwd2
> 
> ### ** Examples
> 
> n <- 30
> t <- rgamma(n, shape=2, scale=100)
> ev <- round(runif(n), 0)
> gammafit(t, ev)
$par
[1]  3.440186 99.036348

$value
[1] 88.70361

$feval
[1] 68

$restarts
[1] 0

$convergence
[1] 0

$message
[1] "Successful convergence"

> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>