Inline. Bert Gunter
"The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Mon, Aug 15, 2016 at 11:43 PM, <g.maub...@weinwolf.de> wrote: > Hi Greg > and all others who replied to my question, > > many thanks for all your answers and help. Currently I store all my > objects in .GlobalEnv = Workspace. I am not yet familiar working with > different environments nor did I see that this would be necessary for my > analysis. > > Could you explain why working with different environments would be > helpful? > > You suggested to read variables into lists rather than storing them in > global variables. This sounds interesting. Could you provide an example of > how to define and use this? It sounds to me as if you really need to spend some time with an R tutorial or two before you do anything else. There are many good ones on the web. See here for some suggestions: https://www.rstudio.com/online-learning/#R While you may reasonably expect some help with R programming and related matters here, you should not expect this list to do your homework for you, at least IMHO (others may disagree). Cheers, Bert > > Kind regards > > Georg > > > > Von: Greg Snow <538...@gmail.com> > An: g.maub...@weinwolf.de, > Kopie: r-help <r-help@r-project.org> > Datum: 15.08.2016 20:33 > Betreff: Re: [R] Accessing an object using a string > > > > The names function is a primitive, which means that if it does not > already do what you want, it is generally not going to be easy to > coerce it to do it. > > However, the names of an object are generally stored as an attribute > of that object, which can be accessed using the attr or attributes > functions. If you change your code to not use the names function and > instead use attr or attributes to access the names then it should work > for you. > > > You may also want to consider changing your workflow to have your data > objects read into a list rather than global variables, then process > using lapply/sapply (this would require a change in how your data is > saved from your example, but if you can change that then everything > after can be cleaner/simpler/easier/more fool proof/etc.) > > > On Mon, Aug 15, 2016 at 2:49 AM, <g.maub...@weinwolf.de> wrote: >> Hi All, >> >> I would like to access an object using a sting. >> >> # Create example dataset >> var1 <- c(1, 2, 3) >> var2 <- c(4, 5, 6) >> data1 <- data.frame(var1, var2) >> >> var3 <- c(7, 8, 9) >> var4 <- c(10, 11, 12) >> data2 <- data.frame(var3, var4) >> >> save(file = "c:/temp/test.RData", list = c("data1", "data2")) >> >> # Define function >> t_load_dataset <- function(file_path, >> file_name) { >> file_location <- file.path(file_path, file_name) >> >> print(paste0('Loading ', file_location, " ...")) >> cat("\n") >> >> object_list <- load(file = file_location, >> envir = .GlobalEnv) >> >> print(paste(length(object_list), "dataset(s) loaded from", >> file_location)) >> cat("\n") >> >> print("The following objects were loaded:") >> print(object_list) >> cat("\n") >> >> for (i in object_list) { >> print(paste0("Object '", i, "' in '", file_name, "' contains:")) >> str(i) >> names(i) # does not work >> } >> } >> >> I have only the character vector object_list containing the names of the >> objects as strings. I would like to access the objects in object_list to >> be able to print the names of the variables within the object (usuallly > a >> data frame). >> >> Is it possible to do this? How is it done? >> >> Kind regards >> >> Georg >> >> ______________________________________________ >> 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. > > > > -- > Gregory (Greg) L. Snow Ph.D. > 538...@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.
