The following worked for me (put together after reading ? textConnection). Put simply, all read/write command work with "connections", which are if you like "devices that know how to read or write things". textConnection creates such a device that writes (or reads if we used open="r") to/from an already existing vector. If the file argument to write.csv is not a connection, then it is interpreted as a file name, and a connection to read/write on that file is automatically made for you. The description in ?write.csv explains this part.
x <- character() y<-textConnection("x", open="w") write.csv(iris,file=y) close(y) Haris Skiadas Department of Mathematics and Computer Science Hanover College On Feb 29, 2008, at 4:37 AM, Tristan Casey wrote: > Well that is certainly good news if write.csv output can be stored > directly to a character vector! > > I have tried to specify a vector within the file="" argument for > example; > > write.csv(a,file="b") where b is a preexisting character vector > > This does not work. Do I need to define b as something else, like a > textConnection? > > >> Date: Fri, 29 Feb 2008 09:16:11 +0000 >> From: [EMAIL PROTECTED] >> To: [EMAIL PROTECTED] >> CC: [EMAIL PROTECTED]; r-help@r-project.org >> Subject: RE: [R] write.csv +RMySQL request >> >> On Fri, 29 Feb 2008, Tristan Casey wrote: >> >>> Ahh, my apologies I must admit that I don't fully understand >>> textConnections fully. I have been reading up on th RODBC package >>> as an >>> alternative to RMySQL. >>> >>> With the file argument in write.csv, are you saying it is >>> possible to >>> write the csv formated data directly to a cell in a MySQL >>> database? I am >>> unsure what the variable 'con' must consist of. >> >> No, that it is possible to write it to an R character vector. >> >>> Would this need to be a character string that initially connects >>> to the >>> database (dbConnect) then pastes the MySQL query? I am unsure how to >>> specify where the data is going with the file/connection argument. >>> >>> Thanks >>> >>> >>>> Date: Fri, 29 Feb 2008 08:44:58 +0000 >>>> From: [EMAIL PROTECTED] >>>> To: [EMAIL PROTECTED] >>>> CC: [EMAIL PROTECTED]; r-help@r-project.org >>>> Subject: RE: [R] write.csv +RMySQL request >>>> >>>> On Fri, 29 Feb 2008, Tristan Casey wrote: >>>> >>>>> Thanks again for your help. >>>>> >>>>> I am wanting my variable to store a character string exactly as >>>>> the write.csv function would store as a csv text file; >>>>> >>>>> IE: My goal is to store a data frame of this construction; >>>>> >>>>> x1 x2 >>>>> 1 2 >>>>> 3 4 >>>>> >>>>> as "X1","X2",1,2,3,4 (the same format as CSV). >>>>> >>>>> I am aware of the file argument, however that is the problem, >>>>> storing to >>>>> a physical text file and then importing into the SQL database >>>>> is a very >>>>> inefficient way of doing things, especially when I can use >>>>> RMySQL to >>>>> send commands directly to the database. >>>> >>>> You seem however unaware of text connections. Neither of us >>>> said anything >>>> about using a 'physical text file', and the documentation for >>>> write.csv says >>>> >>>> file: either a character string naming a file or a >>>> connection open >>>> for writing. '""' indicates output to the console. >>>> >>>> A 'text connection; is not a file (physical or otherwise). >>>> >>>> >>>>> >>>>> Kind Regards, >>>>> >>>>> Tristan Casey BPsySci (UQ) >>>>> + 4 Festa Court, Capalaba, QLD 4157 >>>>> H 8/33 Lilly St, Greenslopes, QLD 4120 >>>>> 0450 033 948 >>>>> >>>>> >>>>> >>>>>> Date: Fri, 29 Feb 2008 05:12:04 +0000 >>>>>> From: [EMAIL PROTECTED] >>>>>> To: [EMAIL PROTECTED] >>>>>> CC: [EMAIL PROTECTED]; r-help@r-project.org >>>>>> Subject: Re: [R] write.csv +RMySQL request >>>>>> >>>>>> On Thu, 28 Feb 2008, jim holtman wrote: >>>>>> >>>>>>> ?capture.output >>>>>>> >>>>>>> myoutput <- capture.output(write.csv(...)) >>>>>> >>>>>> It would be better to write directly to a text connection: see >>>>>> the 'file' >>>>>> argument to write.csv. >>>>>> >>>>>>> On Thu, Feb 28, 2008 at 7:34 PM, Tristan Casey >>>>>>> <[EMAIL PROTECTED]> wrote: >>>>>>>> Hello, >>>>>>>> >>>>>>>> I am relatively new to R and learning its ins and outs. As >>>>>>>> part of a website I am building, I need to read and write >>>>>>>> csv files directly from an SQL database. Basically I want to >>>>>>>> convert R variables (dataframes) into CSV format, store them >>>>>>>> as another R variable (as a properly formatted text string >>>>>>>> suitable for csv reading) and then send this to one row in a >>>>>>>> database. >>>>>>>> >>>>>>>> The SQL part is fine, the problem arises because I cannot >>>>>>>> capture the output of write.csv! It posts to the terminal >>>>>>>> when file="" is used, however I also want to store it. Does >>>>>>>> anyone have any ideas? >>>>>>>> >>>>>>>> Thanks in advance! >>>>>> >>>>>> -- >>>>>> Brian D. Ripley, [EMAIL PROTECTED] >>>>>> Professor of Applied Statistics, http://www.stats.ox.ac.uk/ >>>>>> ~ripley/ >>>>>> University of Oxford, Tel: +44 1865 272861 (self) >>>>>> 1 South Parks Road, +44 1865 272866 (PA) >>>>>> Oxford OX1 3TG, UK Fax: +44 1865 272595 >>>>> >>>>> _________________________________________________________________ >>>>> Your Future Starts Here. Dream it? Then be it! Find it at >>>>> www.seek.com.au >>>>> http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek% >>>>> 2Ecom%2Eau%2F%3Ftracking%3Dsk%3Ahet%3Ask%3Anine%3A0%3Ahot% >>>>> 3Atext&_t=764565661&_r=OCT07_endtext_Future&_m=EXT >>>> >>>> -- >>>> Brian D. Ripley, [EMAIL PROTECTED] >>>> Professor of Applied Statistics, http://www.stats.ox.ac.uk/ >>>> ~ripley/ >>>> University of Oxford, Tel: +44 1865 272861 (self) >>>> 1 South Parks Road, +44 1865 272866 (PA) >>>> Oxford OX1 3TG, UK Fax: +44 1865 272595 >>> >>> _________________________________________________________________ >>> Your Future Starts Here. Dream it? Then be it! Find it at >>> www.seek.com.au >>> http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek% >>> 2Ecom%2Eau%2F%3Ftracking%3Dsk%3Ahet%3Ask%3Anine%3A0%3Ahot% >>> 3Atext&_t=764565661&_r=OCT07_endtext_Future&_m=EXT >> >> -- >> Brian D. Ripley, [EMAIL PROTECTED] >> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ >> University of Oxford, Tel: +44 1865 272861 (self) >> 1 South Parks Road, +44 1865 272866 (PA) >> Oxford OX1 3TG, UK Fax: +44 1865 272595 > ______________________________________________ R-help@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.