Ah, yes, try 'as.data.frame" on it. Jim
On Thu, Sep 27, 2018 at 6:00 PM Luigi Marongiu <marongiu.lu...@gmail.com> wrote: > > Thank you Jim, > this requires the definition of an ad hoc function; strange that R > does not have a function for this purpose... > Anyway, it works but it changes the structure of the data. By > redefining the dataframe as I did, I obtain: > > > df > [1] A B C > <0 rows> (or 0-length row.names) > > str(df) > 'data.frame': 0 obs. of 3 variables: > $ A: num > $ B: num > $ C: num > > When applying your function, I get: > > > df > $A > NULL > > $B > NULL > > $C > NULL > > > str(df) > List of 3 > $ A: NULL > $ B: NULL > $ C: NULL > > The dataframe has become a list. Would that affect downstream applications? > > Thank you, > Luigi > On Thu, Sep 27, 2018 at 9:45 AM Jim Lemon <drjimle...@gmail.com> wrote: > > > > Hi Luigi, > > Maybe this: > > > > testdf<-data.frame(A=1,B=2,C=3) > > > testdf > > A B C > > 1 1 2 3 > > toNull<-function(x) return(NULL) > > testdf<-sapply(testdf,toNull) > > > > Jim > > On Thu, Sep 27, 2018 at 5:29 PM Luigi Marongiu <marongiu.lu...@gmail.com> > > wrote: > > > > > > Dear all, > > > I would like to erase the content of a dataframe -- but not the > > > dataframe itself -- in a simple and fast way. > > > At the moment I do that by re-defining the dataframe itself in this way: > > > > > > > df <- data.frame(A = numeric(), > > > + B = numeric(), > > > + C = character()) > > > > # assign > > > > A <- 5 > > > > B <- 0.6 > > > > C <- 103 > > > > # load > > > > R <- cbind(A, B, C) > > > > df <- rbind(df, R) > > > > df > > > A B C > > > 1 5 0.6 103 > > > > # erase > > > > df <- data.frame(A = numeric(), > > > + B = numeric(), > > > + C = character()) > > > > df > > > [1] A B C > > > <0 rows> (or 0-length row.names) > > > > > > > > > > Is there a way to erase the content of the dataframe in a simplier > > > (acting on all the dataframe at once instead of naming each column > > > individually) and nicer (with a specific erasure command instead of > > > re-defyining the object itself) way? > > > > > > Thank you. > > > -- > > > Best regards, > > > Luigi > > > > > > ______________________________________________ > > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > > https://stat.ethz.ch/mailman/listinfo/r-help > > > PLEASE do read the posting guide > > > http://www.R-project.org/posting-guide.html > > > and provide commented, minimal, self-contained, reproducible code. > > > > -- > Best regards, > Luigi ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
