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stabs (version 0.7-1)

Fitting Functions: Fit Functions for Stability Selection

Description

Functions that fit a model until \(q\) variables are selected and that returns the indices (and names) of the selected variables.

Usage

## package lars:
lars.lasso(x, y, q, ...)
lars.stepwise(x, y, q, ...)

## package glmnet: glmnet.lasso(x, y, q, type = c("conservative", "anticonservative"), ...) glmnet.lasso_maxCoef(x, y, q, ...)

Value

A named list with elements

selected

logical. A vector that indicates which variable was selected.

path

logical. A matrix that indicates which variable was selected in which step. Each row represents one variable, the columns represent the steps.

Arguments

x

a matrix containing the predictors or an object of class "mboost".

y

a vector or matrix containing the outcome.

q

number of (unique) selected variables (or groups of variables depending on the model) that are selected on each subsample.

type

a charachter vector specifying if the number of selected variables per subsample is \(\leq q\) (type = "conservative") or \(\geq q\) (type = "anticonservative"). The conservative version ensures that the PFER is controlled.

...

additional arguments passed to the underlying fitting function. See the example on glmnet.lasso_maxCoef in stabsel for the specification of additional arguments via stabsel.

Details

All fitting functions are named after the package and the type of model that is fitted: package_name.model, e.g., glmnet.lasso stands for a lasso model that is fitted using the package glmnet.

glmnet.lasso_maxCoef fits a lasso model with a given penalty parameter and returns the q variables with the largest (absolute) coefficients. If one wants to use glmnet.lasso_maxCoef, one must specify the penalty parameter lambda (via the ... argument) or in stabsel via args.fitfun(lambda = ). Note that usually, the penalty parameter cannot be specified but is chosen such that q variables are selected. For an example on how to use glmnet.lasso_maxCoef see stabsel.

See Also

stabsel for stability selection itself.