## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

No credit card required

# Common grouping functions in plyr

Some of the commonly used grouping function in plyr is listed following with simple example:

• apply - It is used to apply a function to the rows or columns of a matrix, but not generally advisable for data frames as it will coerce to a matrix first.
`# Two dimensional matrix mat <- matrix(seq(1,9), 3, 3)# apply min to rows apply(mat, 1, min)`
• lapply - It is used to apply a function to each element of a list, then get a list back and is the workhorse of other ply functions underneath the code.
`x <- list(a = 1, b = 1:3, c = 10:50) lapply(x, FUN = length)`
• sapply - It is used to apply a function to each element of a list in turn, but get a vector back instead of a list.
` x <- list(a = 1, b = 1:3, c = 10:50) ...`

## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

No credit card required