Package 'gfiUltra'

Title: Generalized Fiducial Inference for Ultrahigh-Dimensional Regression
Description: Variable selection for ultrahigh-dimensional ("large p small n") linear Gaussian models using a fiducial framework allowing to draw inference on the parameters. Reference: Lai, Hannig & Lee (2015) <doi:10.1080/01621459.2014.931237>.
Authors: Stéphane Laurent [aut, cre]
Maintainer: Stéphane Laurent <[email protected]>
License: GPL-3
Version: 1.0.0
Built: 2024-11-21 03:03:54 UTC
Source: https://github.com/stla/gfiultra

Help Index


Fiducial confidence intervals for ultrahigh-dimensional regression

Description

Fiducial confidence intervals of the selected parameters of a ultrahigh-dimensional regression.

Usage

gfiConfInt(gfi, conf = 0.95)

Arguments

gfi

an output of gfiUltra

conf

confidence level

Value

The confidence intervals in a matrix.

See Also

gfiEstimates


Fiducial estimates for ultrahigh-dimensional regression

Description

Fiducial estimates of the selected parameters of a ultrahigh-dimensional regression.

Usage

gfiEstimates(gfi)

Arguments

gfi

an output of gfiUltra

Value

The estimates in a matrix.

See Also

gfiConfInt


Generalized fiducial inference for ultrahigh-dimensional regression

Description

Generates the fiducial simulations of the parameters of a "large p - small n" regression model and returns the selected models with their probability.

Usage

gfiUltra(formula, data, nsims = 1000L, verbose = FALSE, gamma = 1, ...)

Arguments

formula

a formula describing the model

data

dataframe in which to search the variables of the model

nsims

number of fiducial simulations

verbose

whether to print the messages generated by the screening procedure

gamma

tuning parameter; for expert usage only

...

named arguments passed to SIS, such as penalty = "lasso"

Value

A list with two elements: the fiducial simulations in a matrix (fidSims) and a vector giving the probabilities of the selected models (models).

References

Randy C. S. Lai, Jan Hannig & Thomas C. M. Lee. Generalized Fiducial Inference for Ultrahigh-Dimensional Regression. Journal of the American Statistical Association, Volume 110, 2015 - Issue 510, 760-772. <doi:10.1080/01621459.2014.931237>

Examples

# data ####
set.seed(666L)
n <- 300L
p <- 1000L
X <- matrix(rnorm(n * p), nrow = n, ncol = p)
colnames(X) <- paste0("x", 1L:p)
beta <- c(4, 5, 6, 7, 8)
y <- X[, 1L:5L] %*% beta + rnorm(n, sd = 0.9)
dat <- cbind(y, as.data.frame(X))
# fiducial simulations ####
gfi <- gfiUltra(y ~ ., data = dat, nsims = 10000L)
# selected models
gfi$models
# fiducial confidence intervals
gfiConfInt(gfi)
# fiducial estimates
gfiEstimates(gfi)