Thank you for the general code. Really appreciate it.
On Tue, Sep 5, 2023 at 7:59 PM Eric Berger <ericjber...@gmail.com> wrote: > As Duncan points out, ifelse() provides a more general approach than > the specific pmax(). > > Even more generally, you might want to consider the apply() function > (and its relatives sapply(), lapply(), ...) > > For example > > apply(cbind(x1,x2), MAR=1, max) > > In the above statement, x1 and x2 are combined into two columns, MAR=1 > says apply the following function to each row, > and max specifies the function to be applied. The summary is that this > statement applies the max to each row in the object > specified by the first argument. It's very general because you can > replace max by an arbitrary function. > > Similarly, if you get more into R you might modify the above using > chained operations. The following rewrites the above > by piping cbind(x1,x2) into the apply command. Not a necessary feature > to know but eventually will assist you in writing code that does > not require a lot of intermediate variables. > > cbind(x1,x2) |> apply(MAR=1,max) > > On Tue, Sep 5, 2023 at 2:45 PM Duncan Murdoch <murdoch.dun...@gmail.com> > wrote: > > > > On 05/09/2023 4:55 a.m., roslinazairimah zakaria wrote: > > > Hi all, > > > > > > I have these data > > > > > > x1 <- c(116,0,115,137,127,0,0) > > > x2 <- c(0,159,0,0,0,159,127) > > > > > > I want : xx <- c(116,115,137,127,159, 127) > > > > > > I would like to merge these data into one column. Whenever the data is > '0' > > > it will be replaced by the value in the column which is non zero.. > > > I tried append and merge but fail to get what I want. > > > > > > > Others have pointed out pmax(x1, x2). For the sample data, even x1+x2 > > would give the same answer. > > > > The real question is what you want to do if both x1 and x2 have non-zero > > entries, or negative entries: > > > > pmax(x1, x2) > > > > will pick the larger one. It might be zero if the other is negative, > > and that doesn't match your description. > > > > x1+x2 > > > > will just give the sum, which doesn't match your description if both are > > non-zero. > > > > But maybe you want the x1 value unless it is zero, even if it is smaller > > than the x2 value: then you would use > > > > ifelse(x1 != 0, x1, x2) > > > > Similarly > > > > ifelse(x2 != 0, x2, x1) > > > > would prefer the x2 value. > > > > You should think about what you would do in these other cases as well. > > > > Duncan Murdoch > > > > ______________________________________________ > > 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. > -- *Roslinazairimah Zakaria* *Tel: +609-5492370; Fax. No.+609-5492766* *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; roslina...@gmail.com <roslina...@gmail.com>* Faculty of Industrial Sciences & Technology University Malaysia Pahang Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia [[alternative HTML version deleted]] ______________________________________________ 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.
