On Wed, Sep 15, 2010 at 5:05 PM, Uwe Ligges <lig...@statistik.tu-dortmund.de> wrote: > See the R Language Definition manual. Since R knows about lazy evaluation, > it is sometimes neither by reference nor by value. > If you want to think binary, then "by value" fits better than "by > reference". Hi, Can we think it's eventually by value?
For simple functions such as: is(df[[1]], "logical") used to test wheather the first column of data frame df is of type logical, will a new vector be created and used inside the is function? Another example, dbWriteTable(con, "tablename", df) will write the content of data frame df into a database table, will a new data frame object created and used inside the dbWriteTable function? Thanks. > > Uwe Ligges > > > > On 05.09.2010 17:19, Xiaobo Gu wrote: >> >> Hi Team, >> >> Can you please tell me the rules of assignment in R, by value or >> by reference. >> >>> From my about 3 months of experience of part time job of R, it seems most >>> times it is by value, especially in function parameter and return values >>> assignment; and it is by reference when referencing container sub-objects of >>> container objects, such as elements of List objects and row/column objects >>> of DataFrame objectes; but it is by value when referencing the smallest unit >>> of element of a container object, such as cell of data frame objects. >> >> >> >> >> >> Xiaobo.Gu >> >> >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list >> 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. > ______________________________________________ R-help@r-project.org mailing list 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.
