Dear R-users,
Something strange happened within the command "levels"
R version 3.6.1
name <- c("a","b","c")
values <- c(1,2,3)
data <- data.frame(name,values)
levels(data$name)
[1] "a" "b" "c"
R version 4.0
name <- c("a","b","c")
values <- c(1,2,3)
data <- data.frame(name,values)
levels(data$name)
[1] NULL
What is happening here?
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Read the NEWS about R4.0.0 [1] (search for stringsAsFactors), or read any of the many announcements in blogs and forums around the Internet. [1] https://cran.r-project.org/doc/manuals/r-release/NEWS.html On July 15, 2020 1:31:06 AM PDT, andy elprama <andy.elprama at gmail.com> wrote:>Dear R-users, > >Something strange happened within the command "levels" > >R version 3.6.1 >name <- c("a","b","c") >values <- c(1,2,3) >data <- data.frame(name,values) >levels(data$name) >[1] "a" "b" "c" > >R version 4.0 >name <- c("a","b","c") >values <- c(1,2,3) >data <- data.frame(name,values) >levels(data$name) >[1] NULL > >What is happening here? > > [[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.-- Sent from my phone. Please excuse my brevity.
Hi Andy, I believe this is because R 4.0 has changed the default behavior of data.frame(). Prior to 4.0, the default was stringsAsFactors=TRUE. In 4.0, the default is stringsAsFactors=FALSE. If you run your code in R 3.6.1 and change the command to data <- data.frame(name,values,stringsAsFactors=FALSE) you will get the same behavior as in R 4.0. HTH, Eric On Wed, Jul 15, 2020 at 6:45 PM andy elprama <andy.elprama at gmail.com> wrote:> Dear R-users, > > Something strange happened within the command "levels" > > R version 3.6.1 > name <- c("a","b","c") > values <- c(1,2,3) > data <- data.frame(name,values) > levels(data$name) > [1] "a" "b" "c" > > R version 4.0 > name <- c("a","b","c") > values <- c(1,2,3) > data <- data.frame(name,values) > levels(data$name) > [1] NULL > > What is happening here? > > [[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. >[[alternative HTML version deleted]]
> On Jul 15, 2020, at 4:31 AM, andy elprama <andy.elprama at gmail.com> wrote: > > Dear R-users, > > Something strange happened within the command "levels" > > R version 3.6.1 > name <- c("a","b","c") > values <- c(1,2,3) > data <- data.frame(name,values) > levels(data$name) > [1] "a" "b" "c" > > R version 4.0 > name <- c("a","b","c") > values <- c(1,2,3) > data <- data.frame(name,values) > levels(data$name) > [1] NULL > > What is happening here?Hi, The default value for 'stringsAsFactors' for data.frame() and read.table() changed from TRUE to FALSE in version 4.0.0, per the news() file: "R now uses a stringsAsFactors = FALSE default, and hence by default no longer converts strings to factors in calls to data.frame() and read.table()." Using 4.0.2: data <- data.frame(name, values, stringsAsFactors = TRUE)> levels(data$name)[1] "a" "b" "c" If you see behavioral changes from one version of R to another, especially major version increments, check the news() file. Regards, Marc Schwartz
Hi Andy: I just checked in "options", and the following appears: $stringsAsFactors [1] FALSE I think this might be it. You may want to look at options() in R-3.6.1. Thanks, Erin Erin Hodgess, PhD mailto: erinm.hodgess at gmail.com On Wed, Jul 15, 2020 at 9:45 AM andy elprama <andy.elprama at gmail.com> wrote:> Dear R-users, > > Something strange happened within the command "levels" > > R version 3.6.1 > name <- c("a","b","c") > values <- c(1,2,3) > data <- data.frame(name,values) > levels(data$name) > [1] "a" "b" "c" > > R version 4.0 > name <- c("a","b","c") > values <- c(1,2,3) > data <- data.frame(name,values) > levels(data$name) > [1] NULL > > What is happening here? > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >[[alternative HTML version deleted]]
There is an interesting item on stringsAsFactors in this useR! 2020 session: https://www.youtube.com/watch?v=X_eDHNVceCU&feature=youtu.be It's about 27 minutes in. Chris Gordon-Smith On 15/07/2020 17:16, Marc Schwartz via R-help wrote:>> On Jul 15, 2020, at 4:31 AM, andy elprama <andy.elprama at gmail.com> wrote: >> >> Dear R-users, >> >> Something strange happened within the command "levels" >> >> R version 3.6.1 >> name <- c("a","b","c") >> values <- c(1,2,3) >> data <- data.frame(name,values) >> levels(data$name) >> [1] "a" "b" "c" >> >> R version 4.0 >> name <- c("a","b","c") >> values <- c(1,2,3) >> data <- data.frame(name,values) >> levels(data$name) >> [1] NULL >> >> What is happening here? > > Hi, > > The default value for 'stringsAsFactors' for data.frame() and read.table() changed from TRUE to FALSE in version 4.0.0, per the news() file: > > "R now uses a stringsAsFactors = FALSE default, and hence by default no longer converts strings to factors in calls to data.frame() and read.table()." > > > Using 4.0.2: > > data <- data.frame(name, values, stringsAsFactors = TRUE) > >> levels(data$name) > [1] "a" "b" "c" > > > If you see behavioral changes from one version of R to another, especially major version increments, check the news() file. > > Regards, > > Marc Schwartz > > > ______________________________________________ > 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.[[alternative HTML version deleted]]