Maybe, atleast for the most used functions, there should be a section in the .Rd file with name "for newbies"?
Kjetil On Fri, Dec 4, 2009 at 6:18 PM, Peng Yu <[email protected]> wrote: > On Fri, Dec 4, 2009 at 3:06 PM, Peng Yu <[email protected]> wrote: >> On Fri, Dec 4, 2009 at 2:35 PM, Greg Snow <[email protected]> wrote: >>> The invert argument seems a likely candidate, you could also do perl=TRUE >>> and use negations within the pattern (but that is probably overkill for >>> your original question). >> >> I don't see 'invert' in the R version (2.7.1) that I use. Here is the >> snip from ?grep >> >> Usage: >> >> grep(pattern, x, ignore.case = FALSE, extended = TRUE, >> perl = FALSE, value = FALSE, fixed = FALSE, useBytes = FALSE) >> >> sub(pattern, replacement, x, >> ignore.case = FALSE, extended = TRUE, perl = FALSE, >> fixed = FALSE, useBytes = FALSE) >> >> gsub(pattern, replacement, x, >> ignore.case = FALSE, extended = TRUE, perl = FALSE, >> fixed = FALSE, useBytes = FALSE) >> >> regexpr(pattern, text, ignore.case = FALSE, extended = TRUE, >> perl = FALSE, fixed = FALSE, useBytes = FALSE) >> >> gregexpr(pattern, text, ignore.case = FALSE, extended = TRUE, >> perl = FALSE, fixed = FALSE, useBytes = FALSE) >> >> >>> Could you explain to us the process that you use to search for answers to >>> your questions before posting? You have been asking quite a few questions >>> that have answers out there if you can find them. If you tell us where you >>> are looking (and why) then we may be able to suggest some different search >>> strategies that will help you find the answers quicker. Also knowing your >>> thought process may help us in designing future help/tutorials that cater >>> more to people learning R for the first time, things that seem obvious to >>> those of us who have been using the current documentation, apparently are >>> not that obvious to some new users (but also realize that the first place >>> that you may think to look may not even occur to some of us that learned >>> computers in a different time, see fortune(89) ). >> >> For this particular problem in the original post, it is due to the >> fact that I use an older R. >> >> But in general, the R help and examples in the help page should be >> improved in terms of the structure. Just as we write a paper, it is >> better to have a hierarchical descriptions (i.e., which is similar to >> the flow of abstract -> introduction -> maintext, in each section that >> appears later, more detailed information should be given; but earlier >> section should give readers general ideas.) > > Here is another bad example. See ?rep. The Usage section has 'rep(x, > ...)'. However, '...' is only explained later in Arguments. I know > that it is probably because '...' is from functions underlying rep(). > But it does not matter to end users whether they are from an > underlying function or not. Why not put the arguments in the Usage > section? > > Similar cases can be found in the help of many functions. > >> The current way to organizing the help is less satisfactory. >> Description->Usage->Arguments >> >> This may be good if you have already what you should look for. But if >> you are new to it, you will be easily lost. For example, many >> functions are given in Usage without been explained what the >> difference between them until very late, or no explicit explanations >> at all. But having such descriptions on the differences can help users >> choose the appropriate ones. >> >> Some of informative examples should be put forward to help newbies >> understand how to use each function, rather than put at the end of the >> help page. Many examples in the help page requires previous knowledge >> in other functions. In general, it is better to have the information >> on each help page self contained. >> >> Another problem is not due to the help of R, but the design of R >> itself --- there many specially case to use a function. For example, >> x[1:2,] is a matrix but x[1,] is a vector. >> >>> x=matrix(1:6,nr=3) >>> x[1:2,] >> [,1] [,2] >> [1,] 1 4 >> [2,] 2 5 >>> x[1,] >> [1] 1 4 >> >> I know that somebody that has worked with R for over 10 years don't >> know why (It may be because he doesn't care). But I have to ask the >> mailing list to understand that I have to use the option 'drop' in >> order to get a matrix as the returned value. >>> x[1,,drop=F] >> [,1] [,2] >> [1,] 1 4 >> >> If I were the original designer of R, I would make the interface more >> orthogonal (this is the usual way to reduce complexity in software). >> For example, [] would always return a matrix, if I want to reduce its >> dimension, I will have another function to do so. >> >> Have many special cases although might be convenient in some cases. >> But they may also cause confusions and may cause some delicate bugs >> that are to figure out especially to newbies. >> >> The above are my current thoughts. Let me know if it makes sense to you or >> not. >> >>>> -----Original Message----- >>>> From: [email protected] [mailto:r-help-boun...@r- >>>> project.org] On Behalf Of Peng Yu >>>> Sent: Friday, December 04, 2009 12:43 PM >>>> To: [email protected] >>>> Subject: Re: [R] grep() exclude certain patterns? >>>> >>>> On Fri, Dec 4, 2009 at 11:54 AM, Duncan Murdoch <[email protected]> >>>> wrote: >>>> > On 04/12/2009 12:52 PM, Peng Yu wrote: >>>> >> >>>> >> The external grep program has an option -v to select non-matching >>>> >> lines. I'm wondering if how to exclude certain patterns in grep() in >>>> >> R? >>>> >> >>>> > >>>> > ?grep >>>> >>>> I don't see which argument to use. >>>> >>>> ______________________________________________ >>>> [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. >>> >> > > ______________________________________________ > [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. > ______________________________________________ [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.
