[R] Help with dplyr

[William Dunlap]

Did you mean to add stringsAsFactors=FALSE to the following call to
data.frame?
   bin <- data.frame(
      pred = pred,
      bin = cut(pred, breaks = Breaks, include.lowest = TRUE))
Since cut() produces a factor you would also have to convert it to character
to make stringAsFactors=FALSE to have an effect.
   bin <- data.frame(stringsAsFactors=FALSE,
      pred = pred,
      bin = as.character(cut(pred, breaks = Breaks, include.lowest = TRUE)))

However, I suspect that things would work out better if all the calls to
cut used the same breaks and then leaving it as a factor would be fine.


Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Thu, Nov 5, 2015 at 5:45 PM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
wrote:

> Yes,  that was my intention, but it appears I may not have read his code
> carefully enough.
> ---------------------------------------------------------------------------
> Jeff Newmiller                        The     .....       .....  Go Live...
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> Sent from my phone. Please excuse my brevity.
>
> On November 5, 2015 5:23:38 PM PST, David Winsemius <
> dwinsemius at comcast.net> wrote:
> >
> >> On Nov 5, 2015, at 4:58 PM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
> >wrote:
> >>
> >> Solution is to always use the stringsAsFactors=TRUE option in your
> >data.frame() function calls.
> >
> >Since that is the default, I’m wondering if you meant to say FALSE?
> >
> >—
> >David.
> >>
>
> >---------------------------------------------------------------------------
> >> Jeff Newmiller                        The     .....       .....  Go
> >Live...
> >> DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live
> >Go...
> >>                                      Live:   OO#.. Dead: OO#..
> >Playing
> >> Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
> >> /Software/Embedded Controllers)               .OO#.       .OO#.
> >rocks...1k
> >>
>
> >---------------------------------------------------------------------------
> >
> >> Sent from my phone. Please excuse my brevity.
> >>
> >> On November 5, 2015 3:59:10 PM PST, Axel Urbiz <axel.urbiz at gmail.com>
> >wrote:
> >>> Hello,
> >>>
> >>> Is there a way to avoid the warning below in dplyr. I’m performing
> >an
> >>> operation within groups, and the warning says that the factors
> >created
> >>> from each group do not have the same levels, and so it coerces the
> >>> factor to character. I’m using this inside a package I’m developing.
> >>> I’d appreciate your recommendation on how to handle this.
> >>>
> >>> library(dplyr)
> >>>
> >>> set.seed(4)
> >>> df <- data.frame(pred = rnorm(100), models = gl(2, 50, 100, labels =
> >>> c("model1", "model2")))
> >>>
> >>> create_bins <- function (pred, nBins) {
> >>> Breaks <- unique(quantile(pred, probs = seq(0, 1, 1/nBins)))
> >>> bin <- data.frame(pred = pred, bin = cut(pred, breaks = Breaks,
> >>> include.lowest = TRUE))
> >>> bin
> >>> }
> >>>
> >>> res_dplyr <- df %>% group_by(models) %>% do(create_bins(.$pred, 10))
> >>> Warning message:
> >>> In rbind_all(out[[1]]) : Unequal factor levels: coercing to
> >character
> >>>
> >>> Thank you,
> >>> Axel.
> >>>
> >>>
> >>>     [[alternative HTML version deleted]]
> >>>
> >>> ______________________________________________
> >>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>> 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.
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> 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.
> >
> >David Winsemius
> >Alameda, CA, USA
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

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