splitstackshape (version 1.4.8)

splitstackshape-package: splitstackshape

Description

Stack and Reshape Datasets After Splitting Concatenated Values

Details

Package:	splitstackshape
Type:	Package
Version:	1.4.8
Date:	2019-04-21
License:	GPL-3

Online data collection tools like Google Forms often export multiple-response questions with data concatenated in cells. The concat.split() family of functions splits such data into separate cells. The package also includes functions to stack groups of columns and to reshape wide data, even when the data are "unbalanced"---something which stats::reshape() does not handle, and which reshape2::melt() and reshape2::dcast() from reshape2 do not easily handle.

Examples

# NOT RUN {
## concat.split
head(cSplit(concat.test, "Likes", drop = TRUE))

## Reshape
set.seed(1)
mydf <- data.frame(id_1 = 1:6, id_2 = c("A", "B"), varA.1 = sample(letters, 6),
                   varA.2 = sample(letters, 6), varA.3 = sample(letters, 6),
                   varB.2 = sample(10, 6), varB.3 = sample(10, 6), 
                   varC.3 = rnorm(6))
mydf
Reshape(mydf, id.vars = c("id_1", "id_2"),
        var.stubs = c("varA", "varB", "varC"))

## Stacked
Stacked(data = mydf, id.vars = c("id_1", "id_2"),
        var.stubs = c("varA", "varB", "varC"),
        sep = ".")
# }
# NOT RUN {
## Processing times
set.seed(1)
Nrow <- 1000000
Ncol <- 10
mybigdf <- cbind(id = 1:Nrow, as.data.frame(matrix(rnorm(Nrow*Ncol),
                                                   nrow=Nrow)))
head(mybigdf)
dim(mybigdf)
tail(mybigdf)
A <- names(mybigdf)
names(mybigdf) <- c("id", paste("varA", 1:3, sep = "_"),
                    paste("varB", 1:4, sep = "_"),
                    paste("varC", 1:3, sep = "_"))
system.time({
   O1 <- Reshape(mybigdf, id.vars = "id",
   var.stubs = c("varA", "varB", "varC"), sep = "_")
   O1 <- O1[order(O1$id, O1$time), ]
})
system.time({
   O2 <- merged.stack(mybigdf, id.vars="id",
   var.stubs=c("varA", "varB", "varC"), sep = "_")
})
system.time({
   O3 <- Stacked(mybigdf, id.vars="id",
   var.stubs=c("varA", "varB", "varC"), sep = "_")
})
DT <- data.table(mybigdf)
system.time({
   O4 <- merged.stack(DT, id.vars="id",
   var.stubs=c("varA", "varB", "varC"), sep = "_")
})
# }
# NOT RUN {
# }