| transform {base} | R Documentation |
Transform an Object, e.g. a Data Frame
Description
transform is a generic function, which—at least
currently—only does anything useful with
dataframes. transform.default converts its first argument to
a dataframe if possible and calls transform.data.frame.
Usage
transform(x, ...)
transform.default(x, ...)
transform.data.frame(x, ...)
Arguments
x |
The object to be transformed |
... |
Further arguments of the form |
Details
The ... arguments to transform.data.frame are tagged
vector expressions, which are evaluated in the dataframe
x. The tags are matched against names(x), and for
those that match, the value replace the corresponding variable in
x, and the others are appended to x.
Value
The modified value of x.
Note
If some of the values are not vectors of the appropriate length, you deserve whatever you get!
Author(s)
Peter Dalgaard
See Also
subset,
list,
data.frame
Examples
data(airquality)
transform(airquality, Ozone = -Ozone)
transform(airquality, new = -Ozone, Temp = (Temp-32)/1.8)
attach(airquality)
transform(Ozone, logOzone = log(Ozone)) # marginally interesting ...
detach(airquality)