stretch_df: Reshape a data frame from "long" to "wide" format

Description

Reshape a data frame by reducing the multiple rows of repeated variables to a single row for each instance (usually a "case" or object) and stretching out the variables that are not repeated within each case.

Usage

stretch_df(x,idvar,to.stretch,ordervar=NA,include.ordervar=TRUE)

Arguments

A data frame.

idvar

A variable that identifies instances (cases or objects).

to.stretch

Which variables are to be stretched out in the single row.

ordervar

Variable that gives the order of the stretched variables.

include.ordervar

Include the ordering variable in the output.

Value

The reshaped data frame.

Details

stretch_df takes a data frame in which at least some instances have multiple rows and reshapes it into a "wide" format with one row per instance. The variable passed as idvar distinguishes the instances, and will be the first column in the new data frame. All other variables in the data frame except those named in to.stretch and ordervar will follow idvar. The variables named in to.stretch will follow the variables that are not repeated in the initial data frame, along with the order variable if include.ordervar is TRUE.

Examples

Run this code

# NOT RUN {
 # create a data frame with two repeated variables
 longdf<-data.frame(ID=c(rep(111,3),rep(222,4),rep(333,6),rep(444,3)),
  name=c(rep("Joe",3),rep("Bob",4),rep("Sue",6),rep("Bea",3)),
  score1=sample(1:10,16,TRUE),score2=sample(0:100,16),
  scoreorder=c(1,2,3,4,3,2,1,4,6,3,5,1,2,1,2,3))
 stretch_df(longdf,"ID",c("score1","score2"),"scoreorder")
# }