Richard O'Keefe
2019-Jul-03 13:27 UTC
[R] Control the variable order after multiple declarations using within
Why not set all the new columns to dummy values to get the order you want and then set them to their final values in the order that works for that? On Thu, 4 Jul 2019 at 00:12, Kevin Thorpe <kevin.thorpe at utoronto.ca> wrote:> > > On Jul 3, 2019, at 3:15 AM, Sebastien Bihorel < > sebastien.bihorel at cognigencorp.com> wrote: > > > > Hi, > > > > The within function can be used to modify data.frames (among other > objects). One can even provide multiple expressions to modify the > data.frame by more than one expression. However, when new variables are > created, they seem to be inserted in the data.frame in the opposite order > they were declared: > > > >> df <- data.frame(a=1) > >> within(df, {b<-a*2; c<-b*3}) > > a c b > > 1 1 6 2 > > > > Is there a way to insert the variables in an order consistent with the > order of declaration (ie, a, b, c)? > > > > One way is to use mutate() from the dplyr package. > > > > Thanks > > > > Sebastien > > > > ______________________________________________ > > 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. > > > -- > Kevin E. Thorpe > Head of Biostatistics, Applied Health Research Centre (AHRC) > Li Ka Shing Knowledge Institute of St. Michael's > Assistant Professor, Dalla Lana School of Public Health > University of Toronto > email: kevin.thorpe at utoronto.ca Tel: 416.864.5776 Fax: 416.864.3016 > > ______________________________________________ > 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]]
Eric Berger
2019-Jul-03 15:25 UTC
[R] Control the variable order after multiple declarations using within
Nice suggestion, Richard. On Wed, Jul 3, 2019 at 4:28 PM Richard O'Keefe <raoknz at gmail.com> wrote:> Why not set all the new columns to dummy values to get the order you > want and then set them to their final values in the order that works > for that? > > > On Thu, 4 Jul 2019 at 00:12, Kevin Thorpe <kevin.thorpe at utoronto.ca> > wrote: > > > > > > On Jul 3, 2019, at 3:15 AM, Sebastien Bihorel < > > sebastien.bihorel at cognigencorp.com> wrote: > > > > > > Hi, > > > > > > The within function can be used to modify data.frames (among other > > objects). One can even provide multiple expressions to modify the > > data.frame by more than one expression. However, when new variables are > > created, they seem to be inserted in the data.frame in the opposite order > > they were declared: > > > > > >> df <- data.frame(a=1) > > >> within(df, {b<-a*2; c<-b*3}) > > > a c b > > > 1 1 6 2 > > > > > > Is there a way to insert the variables in an order consistent with the > > order of declaration (ie, a, b, c)? > > > > > > > One way is to use mutate() from the dplyr package. > > > > > > > Thanks > > > > > > Sebastien > > > > > > ______________________________________________ > > > 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. > > > > > > -- > > Kevin E. Thorpe > > Head of Biostatistics, Applied Health Research Centre (AHRC) > > Li Ka Shing Knowledge Institute of St. Michael's > > Assistant Professor, Dalla Lana School of Public Health > > University of Toronto > > email: kevin.thorpe at utoronto.ca Tel: 416.864.5776 Fax: 416.864.3016 > > > > ______________________________________________ > > 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. >[[alternative HTML version deleted]]
Jeff Newmiller
2019-Jul-03 16:42 UTC
[R] Control the variable order after multiple declarations using within
Dummy columns do have some drawbacks though, if you find yourself working with large data frames. The dummy columns waste memory and time as compared to either reorganizing columns after the `within` or using separate sequential `with` expressions as I previously suggested. I think mutate avoids this overhead also. On July 3, 2019 8:25:32 AM PDT, Eric Berger <ericjberger at gmail.com> wrote:>Nice suggestion, Richard. > >On Wed, Jul 3, 2019 at 4:28 PM Richard O'Keefe <raoknz at gmail.com> >wrote: > >> Why not set all the new columns to dummy values to get the order you >> want and then set them to their final values in the order that works >> for that? >> >> >> On Thu, 4 Jul 2019 at 00:12, Kevin Thorpe <kevin.thorpe at utoronto.ca> >> wrote: >> >> > >> > > On Jul 3, 2019, at 3:15 AM, Sebastien Bihorel < >> > sebastien.bihorel at cognigencorp.com> wrote: >> > > >> > > Hi, >> > > >> > > The within function can be used to modify data.frames (among >other >> > objects). One can even provide multiple expressions to modify the >> > data.frame by more than one expression. However, when new variables >are >> > created, they seem to be inserted in the data.frame in the opposite >order >> > they were declared: >> > > >> > >> df <- data.frame(a=1) >> > >> within(df, {b<-a*2; c<-b*3}) >> > > a c b >> > > 1 1 6 2 >> > > >> > > Is there a way to insert the variables in an order consistent >with the >> > order of declaration (ie, a, b, c)? >> > > >> > >> > One way is to use mutate() from the dplyr package. >> > >> > >> > > Thanks >> > > >> > > Sebastien >> > > >> > > ______________________________________________ >> > > 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. >> > >> > >> > -- >> > Kevin E. Thorpe >> > Head of Biostatistics, Applied Health Research Centre (AHRC) >> > Li Ka Shing Knowledge Institute of St. Michael's >> > Assistant Professor, Dalla Lana School of Public Health >> > University of Toronto >> > email: kevin.thorpe at utoronto.ca Tel: 416.864.5776 Fax: >416.864.3016 >> > >> > ______________________________________________ >> > 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. >> > > [[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.