[R] Using ddply within a function by argument transfer
Ista Zahn
istazahn at gmail.com
Mon Mar 5 02:03:15 CET 2012
Hi,
On Sunday, March 04, 2012 03:28:44 PM Fredrik Karlsson wrote:
> Hi Joshua,
>
> Yes, sorry - I attached an .rda file - maybe it was squashed.
> Anyway, yes, I agree with you that the function in the present state would
> not be of very much help to an end user (and your right in thinking that
> this is not the end implementation of the function, just an example). I too
> cannot find a combination of candidate functions that work.
> What I need is the ability for the user to specify the columns in data to
> be processed by ddply and the data frame itself. So far I have not been
> able to do this using ddply - I guess I'll have to roll my own using for
> loops and data frame subsetting or something similar.
Yes, I think that's right. See here:
http://groups.google.com/group/manipulatr/browse_thread/thread/26bed2ff5197e589
for a discussion of why this is.
Best,
Ista
>
> Thank you for trying!
>
> /Fredrik
>
> On Sun, Mar 4, 2012 at 12:50 PM, Joshua Wiley <jwiley.psych at gmail.com>wrote:
> > Hi,
> >
> > Still no data (either not attached or a format the mail server
> > scrubs), but I made some up. ddply seems to be a bit tricky in that
> > it holds off evaluating its arguments. I honestly am not sure how to
> > get around that---no amount of fancy footwork with eval() or quote()
> > is going to change the internals of ddply. The easiest approach seems
> > to be to change the call to it in the first place. You cannot do this
> > by passing arguments, but you can by using subsitute() to have your
> > test function construct and then evaluate the ddply() call. Here is a
> > working example:
> >
> > require(plyr)
> >
> > pb <- data.frame(Type = sample(6, 30, TRUE),
> >
> > Sex = sample(0:1, 30, TRUE),
> > Speaker = sample(3, 30, TRUE),
> > F1 = rnorm(30))
> >
> > insidefun <- function(x){
> >
> > return(x+1)
> >
> > }
> >
> > testfun <- function(data, factors, x, fun = quote(summarize)) {
> >
> > arglist <- list(data = data, factors = as.quoted(factors), fun = fun, x =
> >
> > x)
> >
> > myd <- substitute(ddply(.data=data,
> >
> > .variables=factors, .fun = fun, norm = x), arglist)
> >
> > out <- eval(myd)
> > return(out)
> >
> > }
> >
> > testfun(pb, c("Type","Sex","Speaker"), x = quote(insidefun(F1)))
> >
> > By the way, in its present state, this is essentially a painfully
> > complex wrapper to ddply and your code would probably be less buggy
> > and easier to understand just using ddply, but presumably you are
> > planning to have some other stuff go on in the real testfun().
> >
> > Cheers,
> >
> > Josh
> >
> > On Sun, Mar 4, 2012 at 9:06 AM, Fredrik Karlsson <dargosch at gmail.com>
> >
> > wrote:
> > > Hi,
> > >
> > > Sorry all - I will provide a reproducable version of this. I am still
> > > seeing the same problem - maybe it is due to me having to use summarize?
> > > Anyway, here is an example (using the data set attached):
> > >
> > > Two test functions:
> > >
> > > insidefun <- function(x){
> > >
> > > return(x+1)
> > >
> > > }
> > >
> > > testfun <- function(data,factors,x){
> > >
> > > datOrig <- ddply(.data=data,
> > >
> > > .variables=as.quoted(factors),
> > > .fun=summarize,
> > > norm=insidefun(x)
> > > )
> > >
> > > }
> > >
> > >> testfun(pb,c("Type","Sex","Speaker"),F1)
> > >
> > > Error in insidefun(x) : object 'x' not found
> > >
> > > Now, if I call ddply directly, it works:
> > >> head(ddply(pb,.(Type,Sex,Speaker),summarize,norm=insidefun(F1)),4)
> > >>
> > > Type Sex Speaker norm
> > >
> > > 1 c f 62 461
> > > 2 c f 62 401
> > > 3 c f 62 601
> > > 4 c f 62 611
> > >
> > > I'm sure I'm doing something stupid - and of course I see that the ddply
> >
> > call
> >
> > > inside the function will have to do some processing in order to get the
> > > arguments in the right mode/class - but I don't know how.
> > >
> > > /Fredrik
> > >
> > >
> > >
> > >
> > > On Sun, Mar 4, 2012 at 6:44 AM, David Winsemius <dwinsemius at comcast.net
> > >
> > >wrote:
> > >> On Mar 4, 2012, at 12:20 AM, Fredrik Karlsson wrote:
> > >> Hi Michael,
> > >>
> > >>> No, sorry - that is neither the problem or the solution.
> > >>>
> > >>> suspicious.vowels(pb,c("Type",**"Sex","Vowel"),F1,F2)
> > >>>
> > >>> Error in mean(y, na.rm = na.rm) : object 'f1' not found
> > >>
> > >> Obviously you have still failed to offer reproducible code to go along
> > >> wiht your questions, but I would observe that in R that f1 is NOT going
> >
> > to
> >
> > >> equal F1.
> > >>
> > >> --
> > >>
> > >>> /Fredrik
> > >>>
> > >>> On Sat, Mar 3, 2012 at 7:04 PM, R. Michael Weylandt <
> > >>>
> > >>> michael.weylandt at gmail.com> wrote:
> > >>> Untested, but it might be simpler than that:
> > >>>> suspicious.vowels(pb,c("Type",**"Sex","Vowel"),"F1",F2)
> > >>>>
> > >>>> Note that "F1" is in quotes but F2 isn't.
> > >>>>
> > >>>> Michael
> > >>>>
> > >>>> On Sat, Mar 3, 2012 at 5:46 PM, Fredrik Karlsson <dargosch at gmail.com>
> > >>>>
> > >>>> wrote:
> > >>>>> Dear list,
> > >>>>>
> > >>>>> Sorry, but I cannot get my head around how and I could pass
> > >>>>> arguments
> > >>>>
> > >>>> along
> > >>>>
> > >>>>> to high-level functions. What I have is a function that would
> > >>>>> benefit
> > >>>>
> > >>>> from
> > >>>>
> > >>>>> me using ddply from the plyr package.
> > >>>>> However, I cannot get the arguments passing part right.
> > >>>>>
> > >>>>> So, this is my function:
> > >>>>> suspicious.vowels <-
> > >>>>>
> > >>>>> function(data,factors,f1,f2,**evaluate.original.params=TRUE) {
> > >>>>>
> > >>>>> datOrig <- ddply(.data=data,
> > >>>>>
> > >>>>> .variables=as.quoted(factors),
> > >>>>> .fun=summarize,
> > >>>>> norm=vector.space(f1,f2)[["**Vector norms"]]
> > >>>>> )
> > >>>>>
> > >>>>> print(datOrig)
> > >>>>>
> > >>>>> }
> > >>>>>
> > >>>>> Of course, if I try to call this function, I get an error message
> > >>>>> telling
> > >>>>>
> > >>>>> me that the "f1" argument does not exist:
> > >>>>> suspicious.vowels(pb,c("Type",**"Sex","Vowel"),"F1",F2)
> > >>>>>
> > >>>>> Error in mean(y, na.rm = na.rm) : object 'f1' not found
> > >>>>>
> > >>>>> However, the corresponding ddply call, when called from the console,
> > >>>>> does
> > >>>>>
> > >>>>> work:
> > >>>>> head(ddply(pb,as.quoted(c("**Type","Sex","Vowel")),**
> > >>>>
> > >>>> summarize,norm=vector.space(**F1,F2)[["Vector
> > >>>>
> > >>>>> norms"]]),4)
> > >>>>> Type Sex Vowel norm
> > >>>>> 1 c f aa 250.1570
> > >>>>> 2 c f aa 497.2711
> > >>>>> 3 c f aa 172.3108
> > >>>>> 4 c f aa 109.4464
> > >>>>> ...
> > >>>>>
> > >>>>> So, how do I modify the function to pass the arguments that I supply
> > >>>>> correctly? I cannot get my head around this enough to find the
> >
> > correct
> >
> > >>>>> combination of deparse /substitute /... to get this right.
> > >>>>>
> > >>>>> I would be thankful for all the help I could get on this.
> > >>>>>
> > >>>>> /Fredrik
> > >>>>>
> > >>>>> --
> > >>>>> "Life is like a trumpet - if you don't put anything into it, you
> >
> > don't
> >
> > >>>> get
> > >>>>
> > >>>>> anything out of it."
> > >>>>>
> > >>>>> [[alternative HTML version deleted]]
> > >>>>>
> > >>>>> ______________________________**________________
> > >>>>> R-help at 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.
> > >>>
> > >>> --
> > >>> "Life is like a trumpet - if you don't put anything into it, you don't
> >
> > get
> >
> > >>> anything out of it."
> > >>>
> > >>> [[alternative HTML version deleted]]
> > >>>
> > >>> ______________________________**________________
> > >>> R-help at 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
> > >
> > > --
> > > "Life is like a trumpet - if you don't put anything into it, you don't
> >
> > get
> >
> > > anything out of it."
> > >
> > > ______________________________________________
> > > 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.
> >
> > --
> > Joshua Wiley
> > Ph.D. Student, Health Psychology
> > Programmer Analyst II, Statistical Consulting Group
> > University of California, Los Angeles
> > https://joshuawiley.com/
More information about the R-help
mailing list