transform(x, ...)
x
| The object to be transformed |
...
|
Further arguments of the form tag=value
|
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
.
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)