/TBEinf

TBE_infty is the exponential dispersion model generated by the Landau distribution and also known as a Tweedie model with power infinity. "TBEinf" computes the density of TBE_\infty by direct calculation, saddlepoint approximation, Fourier inversion, and related methods.

Primary LanguageR

TBEinf

$\text{TBE}_\infty$ is the exponential dispersion model generated by the Landau distribution and also known as a Tweedie model with power infinity.

"TBEinf" computes the density of $\text{TBE}\infty$ by direct calculation, saddlepoint approximation, Fourier inversion, and related methods. "TBEinf" applys $\text{TBE}\infty$ to the generalized linear model for estimation and prediction. The estimation of coefficients is obtained through Iteratively Reweighted Least Squares.

Installation

#install Rtools 3.5 (http://cran.r-project.org/bin/windows/Rtools)
#install.packages("devtools")
#install.packages("Rcpp")
library(devtools)
install_github("xliusufe/TBEinf")

Usage

  • TBEinf-manual ------------ Details of the usage of the package.

Example

library(TBEinf)
library(pracma)

set.seed(123)
n <- 800
p <- 15
pp <- p+1
beta_0 <- -0.5*(1:pp)
phi_0 <- 0.05

x <- matrix(runif(n * p), nrow = n, ncol = p)
X <- cbind(1, x)
eta_0 <- X %*% beta_0
m_0 <- -log(- eta_0)
y <- rnorm(n, mean = m_0, sd = phi_0*exp(m_0))

initial <- rep(-0.1, pp)
beta <- TBEinf.glm.fit(y, X, initial)$beta
phi <- TBEinf.glm.fit(y, X, initial)$phi
x_new <- runif(pp)
y_pre <- TBEinf.glm.pre(x_new, beta)

References

Bar-Lev, S.K. (2023). The Exponential Dispersion Model Generated by the Landau Distribution ---A Comprehensive Review and Further Developments. Mathematics. 11(20), 4343.

Dunn, P. K. and Smyth, G. K. (2008). Evaluation of Tweedie exponential dispersion model densities by Fourier inversion. Statistics and Computing. 18, 73--86.

Dunn, P. K. and Smyth, G. K. (2018). Generalized Linear Models with Examples in R. Springer: Berlin/Heidelberg, Germany.

Dunn, P. K. and Smyth, G. K. (2022). Evaluation of Tweedie Exponential Family Models; R Package Version 2.3.5; 2022. Available online: https://cran.r-project.org/web/packages/tweedie/tweedie.pdf

Jorgensen, B. (1997). The Theory of Dispersion Models. Chapman and Hall, London.

Sidi, Avram (1988). A user-friendly extrapolation method for oscillatory infinite integrals. Mathematics of Computation. 51(183), 249--266.

Development

The R-package is developed by Ziyu Xiang (xiangziyu2867@163.com), Xu Liu, Shaul Bar-Lev, Ad Ridder.