[R] wrong name of input file and goto like function

[Uwe Ligges]

Please do read at least some basic R documentation before posting here!

In addition, please read the help pages:

help("file.exists")

help("stop") vs. help("print")

help("break") which is not a function



On 24.07.2011 17:35, Bansal, Vikas wrote:
> Thanks for you reply.I have seen it and I got that we can use this goto function in the form of double loop.
>
> like-
>
> for(j in 1:10)
> {
> df=read.table(define(),fill=T,sep="\t",colClasses = "character")
> if()
> {
> print("wrong name of the file Please enter again ")}
> else{
> break()
> }
> }
>
> but i did not find what should i condition should i give in if statement because when the user will type the wrong name of the file,my code does not execute and just showing the eroor
>
> could not find such file
>
> Can you please tell me what condition i should write so that my code should not stop even if user writes wrong name of input file?
>
> Thanking you,
> Warm Regards
> Vikas Bansal
> Msc Bioinformatics
> Kings College London
> ________________________________________
> From: Bert Gunter [gunter.berton at gene.com]
> Sent: Sunday, July 24, 2011 3:58 PM
> To: Bansal, Vikas
> Cc: r-help at r-project.org
> Subject: Re: [R] wrong name of input file and goto like function
>
> 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<vikas.bansal at kcl.ac.uk>  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
>> ______________________________________________
>> R-help at 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.
>>
>
>
>
> --
> "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
>
> ______________________________________________
> R-help at 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.