Considering the following data frame
df<-data.frame(a=c(1,2,3))
I can show it by doing:
df
or
get("df")
Also, I can give an attribute to it by doing this:
attr(df,"anyAttribute")<-"df attribute"
attributes(df)
$names
[1] "a"
$class
[1] "data.frame"
$row.names
[1] 1 2 3
$anyAttribute
[1] "df attribute"
Is there any way to give attributes to dataframes dynamically?. What I want is something like this:
> attr(get("df"),"anyAttribute")<-"df attribute"
Error in attr(get("df"), "anyAttribute") <- "df attribute" :
destino de la asignación se expande a un objeto fuera del lenguaje
CodePudding user response:
Do you mean this?
r <- `attr<-`(get("df"), "anyAttribute", "df attribute")
attributes(r)
# $names
# [1] "a"
#
# $class
# [1] "data.frame"
#
# $row.names
# [1] 1 2 3
#
# $anyAttribute
# [1] "df attribute"
CodePudding user response:
We can use assign
to update the original object
tmp <- get('df')
attr(tmp, 'anyAttribute') <- 'df attribute'
assign('df', tmp)
-output
> str(df)
'data.frame': 3 obs. of 1 variable:
$ a: num 1 2 3
- attr(*, "anyAttribute")= chr "df attribute"