These are elementary programming constructs. I would suggest you take a look at an online basic (as in elementary, not the Basic language) programming tutorial to see how to do this sort of thing. R does it like many other languages (with ?for, ?while, ?if, etc.).
-- Bert On Sun, Jul 24, 2011 at 7:05 AM, Bansal, Vikas <[email protected]> wrote: > Dear all, > > I have a question and need your help please. > I have the following code which is asking user to enter the name of their > file. > > define<- function() > { > readline("enter the name of your file: ") > } > > df=read.table(define(),fill=T,sep="\t",colClasses = "character") > > Now I want if user will input wrong name of file the code should not end and > it should show a message- > > if() > { > print("wrong name of the file Please enter again ") > > } > > now I want to ask what should be the condition of if so that if user will > input wrong file name it will show this message and then i want to use > something like goto so that it should again start with the code which is > before if condition- > > df=read.table(define(),fill=T,sep="\t",colClasses = "character") > > > > > so the code should be- > > define<- function(x) > { > readline("enter the name of your file: ") > } > > df=read.table(define(),fill=T,sep="\t",colClasses = "character") > ##starline > > > if(## some condition here) > { > print("wrong name of the file Please enter again ") > ## some goto function so that it should goto (starline) > } > > > > > > > > Thanking you, > Warm Regards > Vikas Bansal > Msc Bioinformatics > Kings College London > ______________________________________________ > [email protected] 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. > -- "Men by nature long to get on to the ultimate truths, and will often be impatient with elementary studies or fight shy of them. If it were possible to reach the ultimate truths without the elementary studies usually prefixed to them, these would not be preparatory studies but superfluous diversions." -- Maimonides (1135-1204) Bert Gunter Genentech Nonclinical Biostatistics ______________________________________________ [email protected] 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.
