[R] simple question on data frames assignment

[Michael Artz]

Why am I better off with true and false?

On Thu, Apr 7, 2016 at 8:41 AM, Hadley Wickham <h.wickham at gmail.com> wrote:

> == is also vectorised, and you're better off with TRUE and FALSE
> rather than 1 and 0, so I'd recommend:
>
> colordata$response <- colordata$color == 'blue'
>
> Hadley
>
> On Thu, Apr 7, 2016 at 6:52 AM, David Barron <dnbarron at gmail.com> wrote:
> > ifelse is vectorised, so just use that without the loop.
> >
> > colordata$response <- ifelse(colordata$color == 'blue', 1, 0)
> >
> > David
> >
> > On 7 April 2016 at 12:41, Michael Artz <michaeleartz at gmail.com> wrote:
> >
> >> Hi I'm not sure how to ask this, but its a very easy question to answer
> for
> >> an R person.
> >>
> >> What is an easy way to check for a column value and then assigne a new
> >> column a value based on that old column value?
> >>
> >> For example, Im doing
> >>  colordata <- data.frame(id = c(1,2,3,4,5), color = c("blue", "red",
> >> "green", "blue", "orange"))
> >>  for (i in 1:nrow(colordata)){
> >>    colordata$response[i] <- ifelse(colordata[i,"color"] == "blue", 1, 0)
> >>  }
> >>
> >> which works,  but I don't want to use the for loop I want to "vecotrize"
> >> this.  How would this be implemented?
> >>
> >>         [[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]]
> >
> > ______________________________________________
> > 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.
>
>
>
> --
> http://hadley.nz
>

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