melt-data-frame-da: Melt a data frame

In reshape: Flexibly Reshape Data

Melt a data frame

Description

Melt a data frame into form suitable for easy casting.

Usage

## S3 method for class 'data.frame'
melt(data, id.vars, measure.vars,
  variable_name = "variable", na.rm = !preserve.na, preserve.na = TRUE, ...)

Arguments

data	Data set to melt
id.vars	Id variables. If blank, will use all non measure.vars variables. Can be integer (variable position) or string (variable name)
measure.vars	Measured variables. If blank, will use all non id.vars variables. Can be integer (variable position) or string (variable name)
variable_name	Name of the variable that will store the names of the original variables
na.rm	Should NA values be removed from the data set?
preserve.na	Old argument name, now deprecated
...	other arguments ignored

Details

You need to tell melt which of your variables are id variables, and which are measured variables. If you only supply one of id.vars and measure.vars, melt will assume the remainder of the variables in the data set belong to the other. If you supply neither, melt will assume factor and character variables are id variables, and all others are measured.

Value

molten data

Author(s)

Hadley Wickham <[e-mail]>

See Also

http://had.co.nz/reshape/

Examples

head(melt(tips))
names(airquality) <- tolower(names(airquality))
melt(airquality, id=c("month", "day"))
names(ChickWeight) <- tolower(names(ChickWeight))
melt(ChickWeight, id=2:4)

reshape documentation built on April 12, 2022, 5:07 p.m.