dt_pivot_longer: Pivot data from wide to long

In tidyfast: Fast Tidying of Data

Description

dt_pivot_wider() "widens" data, increasing the number of columns and decreasing the number of rows. The inverse transformation is dt_pivot_longer(). Syntax based on the tidyr equivalents.

Usage

dt_pivot_longer(
  dt_,
  cols = NULL,
  names_to = "name",
  values_to = "value",
  values_drop_na = FALSE,
  ...
)

Arguments

dt_	The data table to pivot longer
cols	Column selection. If empty, uses all columns. Can use -colname to unselect column(s)
names_to	Name of the new "names" column. Must be a string.
values_to	Name of the new "values" column. Must be a string.
values_drop_na	If TRUE, rows will be dropped that contain NAs.
...	Additional arguments to pass to 'melt.data.table()'

Value

A reshaped data.table into longer format

Examples

library(data.table)
example_dt <- data.table(x = c(1,2,3), y = c(4,5,6), z = c("a", "b", "c"))

dt_pivot_longer(example_dt,
                cols = c(x, y),
                names_to = "stuff",
                values_to = "things")

dt_pivot_longer(example_dt,
                cols = -z,
                names_to = "stuff",
                values_to = "things")

tidyfast documentation built on March 20, 2020, 5:08 p.m.