Um, if you insist on doing it that way, at least use
assign(varname, as.vector(get(varname)))
-pd
> On 4 Dec 2017, at 22:46 , Love Bohman <love.boh...@sociology.su.se> wrote:
>
> Hi!
> Thanks for the replies!
> I understand people more accustomed to R doesn't like looping much, and that
> thinking about loops is something I do since I worked with Stata a lot. The
> syntax from Peter Dalgaard was really clever, and I learned a lot from it,
> even though it didn't solve my problem (I guess it wasn't very well
> explained). My problem was basically that I have a data matrix consisting of
> just 1 row, and I want to convert that row into a vector. However, when
> trying to do that dynamically, I couldn't get R to read the right hand side
> of the syntax as a variable name instead of a string. However, together with
> a colleague I finally solved it with the (eval(as.name()) function (I include
> the loop I used below). I understand that looping isn't kosher among you more
> devoted R-users, and eventually I hope I will learn to use lists in the
> future instead.
>
> Thanks!
> Love
>
>
> for (year in 2000:2007){
> varname <- paste0("aa_",year)
> assign(paste0(varname), as.vector(eval(as.name(varname))))
> }
>
> -----Ursprungligt meddelande-----
> Från: peter dalgaard [mailto:pda...@gmail.com]
> Skickat: den 4 december 2017 16:39
> Till: Love Bohman <love.boh...@sociology.su.se>
> Kopia: r-help@r-project.org
> Ämne: Re: [R] Dynamic reference, right-hand side of function
>
> The generic rule is that R is not a macro language, so looping of names of
> things gets awkward. It is usually easier to use compound objects like lists
> and iterate over them. E.g.
>
> datanames <- paste0("aa_", 2000:2007)
> datalist <- lapply(datanames, get)
> names(datalist) <- datanames
> col1 <- lapply(datalist, "[[", 1)
> colnum <- lapply(col1, as.numeric)
>
> (The 2nd line assumes that the damage has already been done so that you have
> aa_2000 ... aa_2007 in your workspace. You might alternatively create the
> list directly while importing the data.)
>
> -pd
>
>> On 4 Dec 2017, at 12:33 , Love Bohman <love.boh...@sociology.su.se> wrote:
>>
>> Hi R-users!
>> Being new to R, and a fairly advanced Stata-user, I guess part of my problem
>> is that my mindset (and probably my language as well) is wrong. Anyway, I
>> have what I guess is a rather simple problem, that I now without success
>> spent days trying to solve.
>>
>> I have a bunch of datasets imported from Stata that is labelled aa_2000
>> aa_2001 aa_2002, etc. Each dataset is imported as a matrix, and consists of
>> one column only. The columns consists of integer numbers. I need to convert
>> the data to vectors, which I found several ways to do. I use, for example:
>> aa_2000 <- as.numeric(aa_2000[,1])
>> However, when trying to automate the task, so I don't have to write a line
>> of code for each dataset, I get stuck. Since I'm a Stata user, my first
>> attempt is trying to make a loop in order to loop over all datasets.
>> However, I manage to write a loop that works for the left-hand side of the
>> syntax, but not for the right-hand side.
>> I have included some examples from my struggles to solve the issue below,
>> what they all have in common is that I don't manage to call for any "macro"
>> (is that only a Stata-word?) in the right hand side of the functions. When I
>> try to replace the static reference with a dynamic one (like in the
>> left-hand side), the syntax just doesn't work.
>>
>> I would very much appreciate some help with this issue!
>> All the best,
>> Love
>>
>> year <- 2002
>> dataname <- paste0("aa_",year)
>> assign(paste0(dataname), as.numeric(aa_2002[,1]))
>>
>> year <- 2003
>> assign(paste0("aa_",year), as.numeric(aa_2003))
>>
>> year <- 2005
>> assign(paste0("aa_",year), aa_2005[,1])
>>
>> list1 <- c(2000:2007)
>> list1[c(7)]
>> assign(paste0("aa_",list1[c(7)]), as.numeric(paste0(aa_2006)))
>>
>>
>> [[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.
>
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000
> Frederiksberg, Denmark
> Phone: (+45)38153501
> Office: A 4.23
> Email: pd....@cbs.dk Priv: pda...@gmail.com
>
>
>
>
>
>
>
>
>
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd....@cbs.dk Priv: pda...@gmail.com
______________________________________________
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.
