measure: measure

In nc: Named Capture to Data Tables

measure

Description

Computes a value to be used as measure.vars argument to melt.data.table. NOTE: only works on newer versions of data.table that include the measure function.

Usage

measure(..., cols)

Arguments

...	Regular expression pattern list, passed to capture_first_vec with cols as subject.
cols	Character vector, column names to match with regex.

Details

measure_multiple is called if there is a capture group named "column" and measure_single is called otherwise.

Value

List or vector to use as measure.vars argument to melt.data.table.

Author(s)

Toby Dylan Hocking

Examples

if("measure" %in% ls(asNamespace("data.table"))){
  library(data.table)
  iris.dt <- data.table(datasets::iris[c(1,150),])
  melt(iris.dt, measure=nc::measure(part  =".*", "[.]", dim   =".*"))
  melt(iris.dt, measure=nc::measure(column=".*", "[.]", dim   =".*"))
  melt(iris.dt, measure=nc::measure(part  =".*", "[.]", column=".*"))
}

nc documentation built on Sept. 1, 2023, 1:07 a.m.