| Type: | Package | 
| Title: | Perform Permutation Test on General Linear and Mixed Linear Regression | 
| Version: | 0.1.9 | 
| 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. | 
| License: | GPL-3 | 
| Encoding: | UTF-8 | 
| Imports: | lmerTest,stats | 
| RoxygenNote: | 7.2.3 | 
| NeedsCompilation: | no | 
| Packaged: | 2023-04-16 17:55:41 UTC; Administrator | 
| Author: | Wentao Zeng [aut, cre, cph] | 
| Maintainer: | Wentao Zeng <wentaozeng@aliyun.com> | 
| Repository: | CRAN | 
| Date/Publication: | 2023-04-18 14:10:06 UTC | 
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)