Help with dplyr

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. 

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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.


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