Package 'lmerPerm'

Title: Perform Permutation Test on General Linear and Mixed Linear Regression
Description: We provide a solution for performing permutation tests on linear and mixed linear regression models. It allows users to obtain accurate p-values without making distributional assumptions about the data. By generating a null distribution of the test statistics through repeated permutations of the response variable, permutation tests provide a powerful alternative to traditional parameter tests (Holt et al. (2023) <doi:10.1007/s10683-023-09799-6>). In this early version, we focus on the permutation tests over observed t values of beta coefficients, i.e.original t values generated by parameter tests. After generating a null distribution of the test statistic through repeated permutations of the response variable, each observed t values would be compared to the null distribution to generate a p-value. To improve the efficiency,a stop criterion (Anscombe (1953) <doi:10.1111/j.2517-6161.1953.tb00121.x>) is adopted to force permutation to stop if the estimated standard deviation of the value falls below a fraction of the estimated p-value. By doing so, we avoid the need for massive calculations in exact permutation methods while still generating stable and accurate p-values.
Authors: Wentao Zeng [aut, cre, cph]
Maintainer: Wentao Zeng <[email protected]>
License: GPL-3
Version: 0.1.9
Built: 2024-12-25 06:47:15 UTC
Source: CRAN

Help Index


This function is used for permutation test for general and mixed linear regression

Description

perform general and mixed linear regression by lm function in R base or lmer function in lmer/lmertest package and permutation tests on observed t values of beta coef -ficients

Usage

lmerp(formula, data, thresh, R, mixed, minimum)

Arguments

formula

Regression formula in the form 'y~x1+x2+x3' for general linear function or 'y~x1+x2+x3+(1|x4)' or 'y~x1+x2+x3+(x3|x4)' for mixed linear function

data

A data frame specifying the data to be analysed

thresh

Threshold to stop iteration, default value is 0.1

R

The maximum number of iteration, default value is 1000

mixed

A logic value indicates if you desire to perform mixed linear model or not. Default value is FALSE.

minimum

The minimum number of iteration, default value is 50

Value

A list contains 2 items: Results and T_perm, the former contains results of origi -nal parameter test and results of permutation test including adjusted confident interval (Ci_perm), p values (P_perm), iteration number(Iteration), the later contains a list cont -ains all t values generated in each permutation

Examples

formula<-mpg~cyl
data<-mtcars
my_perm<-lmerp(formula,data)

This function defines the permutation strategry

Description

perform permuation on response variable i.e. y, using the stop criterion suggested by Anscombe

Usage

permute_fun(data, mle)

Arguments

data

A data frame specifying the data to be analysed.

mle

A string that indicated response variable

Value

A data frame containing the data with a permuted y.

Examples

data<-mtcars
permute<-permute_fun(data=data,mle='mpg')

Return t values of general linear model

Description

perform mixed linear regression in lmer/lmertest package for getting observed t values or permutation test

Usage

s1(data, formula)

Arguments

data

A dataframe specifying the data to be analysed

formula

A formula in the form like'y~x1+x2+x3 in lm function

Value

An object of class "lm"

Examples

data<-mtcars
formula<-mpg~cyl
s1(data=data,formula=formula)

Estimate t values of mixed linear model

Description

perform mixed linear regression in lmerTest package for getting observed t values or permutation test

Usage

s2(data, formula)

Arguments

data

A dataframe specifying the data to be analysed

formula

A formula in the form like'y~x1+x2+x3+(1|x4) or like'y~x1+x2+x3 +(x3|x4) in lmer function

Value

An object of class "lmerTest"

Examples

data<-mtcars
formula<-mpg~cyl+(1|gear)
statistic<-s2(data=data,formula=formula)