Thanks for the clarifications.
On Mon, Jun 20, 2011 at 12:40 PM, Bert Gunter <gunter.ber...@gene.com>wrote:
> Sorry, I was unclear. The comment after the second should be:
>
> z[ ,a] # the column of z whose name is the value of the object a
>
> -- Bert
>
> On Mon, Jun 20, 2011 at 9:38 AM, Bert Gunter <bgun...@gene.com> wrote:
> > Ben:
> >
> > 1. One doesn't ask questions like this. Syntax is syntax.
> >
> > 2. This has nothing to do with paste; it's the syntax of "[" ,
> > subscripting/extraction
> >
> > 3. But it does make sense:
> >
> > a <- "b"
> > z <- data.frame(a=1:3, b=4:6)
> > z[ ,"a"] # the "a" column of z
> > z[ ,a] # the column of z with the value of the object a
> >
> > HTH,
> >
> > -- Bert
> >
> >
> > On Mon, Jun 20, 2011 at 9:21 AM, Ben Ganzfried <ben.ganzfr...@gmail.com>
> wrote:
> >> Thanks! Very glad you pointed me to the paste function, it looks very
> >> helpful.
> >>
> >> I have a quick follow-up after reading through the online tutorial on
> the
> >> "paste" function:
> >>
> >> Why do we need quotation marks around "Major Gleason" and "Minor
> Gleason"
> >> in: output = paste(df [,'Major.Gleason'], df[ ,'Minor.Gleason'],
> sep='+')?
> >> The "paste" function is going to concatenate the first and second
> parameters
> >> and separate them by the "+" sign, so I'm not clear why we need to put
> >> quotation marks around the dataframe column headers...
> >>
> >> Thanks,
> >>
> >> Ben
> >>
> >>
> >> On Mon, Jun 20, 2011 at 11:58 AM, David Winsemius <
> dwinsem...@comcast.net>wrote:
> >>
> >>>
> >>> On Jun 20, 2011, at 11:47 AM, Luke Miller wrote:
> >>>
> >>> If we assume that your data are in a data frame (which doesn't allow
> >>>> spaces in column names, hence the periods in the call below):
> >>>>
> >>>> df = data.frame(Major.Gleason = c(4,5,2,3), Minor.Gleason =
> c(3,2,4,3))
> >>>>>
> >>>>
> >>>> You can paste together the contents of the two columns with a plus
> >>>> sign in between using the paste() function. The sep='' option at the
> >>>> end of the function call specifies that no spaces should be included
> >>>> between pasted items.
> >>>>
> >>>> output = paste(as.character(df [,'Major.Gleason']), '+',
> as.character(df[
> >>>>> ,'Minor.Gleason']), sep='')
> >>>>>
> >>>>
> >>> I do not think the as.character is needed. Coercion to character is
> >>> implicit in the use of paste(). And the sep argument could be "+".
> >>>
> >>> output = paste(df [,'Major.Gleason'], df[ ,'Minor.Gleason'], sep='+')
> >>>
> >>> --
> >>> David.
> >>>
> >>>
> >>>
> >>>> The new object 'output' is a character vector containing the 4 strings
> >>>> you're after:
> >>>>
> >>>> print(output)
> >>>>>
> >>>> [1] "4+3" "5+2" "2+4" "3+3"
> >>>>
> >>>>
> >>>> On Mon, Jun 20, 2011 at 11:31 AM, Ben Ganzfried <
> ben.ganzfr...@gmail.com>
> >>>> wrote:
> >>>>
> >>>>>
> >>>>> Hi --
> >>>>>
> >>>>> I had a pretty quick R question since unfortunately I have not been
> able
> >>>>> to
> >>>>> find an answer on Google. It shouldn't take much more than a minute
> to
> >>>>> answer.
> >>>>>
> >>>>> I'm trying to add up the major gleason grade and minor gleason grade
> for
> >>>>> an
> >>>>> analysis of patients with prostate cancer. One column has values
> under
> >>>>> "Major Gleason" and another column has values under "Minor Gleason."
> For
> >>>>> example,
> >>>>> Major Gleason Minor Gleason
> >>>>> 4 3
> >>>>> 5 2
> >>>>> 2 4
> >>>>> 3 3
> >>>>>
> >>>>> I want my output to be:
> >>>>> "4+3"
> >>>>> "5+2"
> >>>>> "2+4"
> >>>>> "3+3"
> >>>>>
> >>>>> The quasi-pseudocode in Java is basically:
> >>>>>
> >>>>> major = column$majorGleason
> >>>>> minor = column$minorGleason
> >>>>> for item in len(Major Gleason) {
> >>>>> string s = major(item) "+" minor(item);
> >>>>> }
> >>>>> return s;
> >>>>>
> >>>>> But trying the same idea in R:
> >>>>>
> >>>>> string <- major "+" minor
> >>>>>
> >>>>> gives me an error: "unexpected string constant in..."
> >>>>>
> >>>>> I would greatly appreciate any help.
> >>>>>
> >>>>> Thanks,
> >>>>>
> >>>>> Ben
> >>>>>
> >>>>> [[alternative HTML version deleted]]
> >>>>>
> >>>>> ______________________________**________________
> >>>>> R-help@r-project.org mailing list
> >>>>> https://stat.ethz.ch/mailman/**listinfo/r-help<
> https://stat.ethz.ch/mailman/listinfo/r-help>
> >>>>> PLEASE do read the posting guide http://www.R-project.org/**
> >>>>> posting-guide.html <http://www.R-project.org/posting-guide.html>
> >>>>> and provide commented, minimal, self-contained, reproducible code.
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> ___________________________
> >>>> Luke Miller
> >>>> Postdoctoral Researcher
> >>>> Marine Science Center
> >>>> Northeastern University
> >>>> Nahant, MA
> >>>> (781) 581-7370 x318
> >>>>
> >>>> ______________________________**________________
> >>>> R-help@r-project.org mailing list
> >>>> https://stat.ethz.ch/mailman/**listinfo/r-help<
> https://stat.ethz.ch/mailman/listinfo/r-help>
> >>>> PLEASE do read the posting guide http://www.R-project.org/**
> >>>> posting-guide.html <http://www.R-project.org/posting-guide.html>
> >>>> and provide commented, minimal, self-contained, reproducible code.
> >>>>
> >>>
> >>> David Winsemius, MD
> >>> West Hartford, CT
> >>>
> >>>
> >>
> >> [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> 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.
> >>
> >
> >
> >
> > --
> > "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
>
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