transform(x, ...) transform.default(x, ...) transform.data.frame(x, ...)
x
| The object to be transformed |
...
|
Further arguments of the form tag=value
|
transform
is a generic function, whichat least
currentlyonly does anything useful with
dataframes. transform.default
converts its first argument to
a dataframe if possible and calls transform.data.frame
.
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
.
x
.subset
,
list
,
data.frame
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)