permutation {TSDT}

permutation

Description

Permute response, treatment, or response for one treatment arm only.

Usage

permutation(response = NULL, trt = NULL, permute_arm = NULL)

Arguments

response

Response (or other) variable(s) to be permuted. This can be a data.frame of multiple variables (e.g. a data.frame of covariates or a multivariate response).

trt

Treatment variable.

permute_arm

reatment arm to permute.

Details

If a response variable is provided and treatment is not provided the response variable is permuted.

If a treatment variable is provided and response is not provided the treatment variable is permuted.

If a response variable and treatment variable and permute are provided the response variable is permuted only for the treatment arm indicated by permute_arm.

If a response variable and treatment variable are provided, but permute_arm

Value

If permuting response or treatment, returns vector of permuted response or treatment. If permuting response and treatment, returns a list of permuted response and treatment.

Examples

N <- 20
x <- data.frame( 1:N )
names( x ) <- "response"
x$trt <- factor( c( rep( "Experimental", 9 ), rep( "Control", N - 9 ) ) )
x$time <- x$response
x$event <- 0:1

## Permute treatment variable
ex1 <- x[,c("response","trt")]
ex1$permuted_trt <- permutation( trt = ex1$trt )

## Permute response variable
ex2 <- x[,c("response","trt")]
ex2$permuted_response <- permutation( response = ex2$response )

## Permute the response for treatment arm only
ex3 <- x[,c("response","trt")]
permuted3 <- permutation( response = ex3$response, trt = ex3$trt, permute_arm = "Experimental" )
names( permuted3 ) <- paste( "permuted_", names(permuted3), sep = "" )
ex3 <- cbind( ex3, permuted3 )

## Permute response and treatment together
ex4 <- x[,c("response","trt")]
permutation_list4 <- permutation( response = ex4$response, trt = ex4$trt )
ex4$permuted_response <- permutation_list4$response
ex4$permuted_trt <- permutation_list4$trt

## Permute a survival response for treatment arm only
ex5 <- x[,c("time","event","trt")]
permuted5 <- permutation( response = ex5[,c("time","event")], trt = ex5$trt,
                          permute_arm = "Experimental" )
names( permuted5 ) <- paste( "permuted_", names(permuted5), sep = "" )
ex5 <- cbind( ex5, permuted5 )

## Permute a survival outcome and treatment together
ex6 <- x[,c("time","event","trt")]
permutation_list6 <- permutation( response = ex6[,c("time","event")], trt = ex6$trt )
ex6$permuted_time <- permutation_list6$response$time
ex6$permuted_event <- permutation_list6$response$event