Thank you Jeremiah and all others for the assistance. This really helped. On Sat, Aug 6, 2016 at 5:01 AM, jeremiah rounds <roundsjerem...@gmail.com> wrote:
> Something like: > > d = data.frame(score = sample(1:10, 100, replace=TRUE)) > d$score_t = "low" > d$score_t[d$score > 3] = "medium" > d$score_t[d$score >7 ] = "high" > d$score_t = factor(d$score_t, levels = c("low", "medium", "high"), > ordered=TRUE) #set ordered = FALSE for dummy variables > X = model.matrix(~score_t, data=d) > X > > > > On Fri, Aug 5, 2016 at 3:23 PM, Shivi Bhatia <shivipm...@gmail.com> wrote: > >> Thanks you all for the assistance. This really helps. >> >> Hi Bert: While searching nabble i got to know R with factors variables >> there is no need to create dummy variable. However please consider this >> situation: >> I am in the process of building a logistic regression model on NPS data. >> The outcome variable is CE i.e. customer experience which has 3 rating so >> ordinal logistic regression will be used. However most of my variables are >> categorical. For instance one of the variable is agent knowledge which is >> a >> 10 point scale. >> >> This agent knowledge is again a 3 rated scale: high medium low hence i >> need >> to group these 10 values into 3 groups & then as you suggested i can >> directly enter them in the model without creating n-1 categories. >> >> I have worked on SAS extensively hence found this a bit confusing. >> >> Thanks for the help. >> >> On Sat, Aug 6, 2016 at 2:30 AM, Bert Gunter <bgunter.4...@gmail.com> >> wrote: >> >> > Just commenting on the email subject, not the content (which you have >> > already been helped with): there is no need to *ever* create a dummy >> > variable for regression in R if what you mean by this is what is >> > conventionally meant. R will create the model matrix with appropriate >> > "dummy variables" for factors as needed. See ?contrasts and ?C for >> > relevant details and/or consult an appropriate R tutorial. >> > >> > Of course, if this is not what you meant, than ignore. >> > >> > Cheers, >> > Bert >> > >> > >> > Bert Gunter >> > >> > "The trouble with having an open mind is that people keep coming along >> > and sticking things into it." >> > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) >> > >> > >> > On Fri, Aug 5, 2016 at 1:49 PM, <ruipbarra...@sapo.pt> wrote: >> > > Hello, >> > > >> > > Your ifelse will never work because >> > > reasons$salutation== "Mr" & reasons$salutation=="Father" is always >> FALSE >> > > and so is reasons$salutation=="Mrs" & reasons$salutation=="Miss". >> > > Try instead | (or), not & (and). >> > > >> > > Hope this helps, >> > > >> > > Rui Barradas >> > > >> > > >> > > >> > > Citando Shivi Bhatia <shivipm...@gmail.com>: >> > > >> > >> Dear Team, >> > >> >> > >> I need help with the below code in R: >> > >> >> > >> gender_rec<- c('Dr','Father','Mr'=1, 'Miss','MS','Mrs'=2, 3) >> > >> >> > >> reasons$salutation<- gender_rec[reasons$salutation]. >> > >> >> > >> This code gives me the correct output but it overwrites the >> > >> reason$salutation variable. I need to create a new variable gender to >> > >> capture gender details and leave salutation as it is. >> > >> >> > >> i tried the below syntax but it is converting all to 1. >> > >> >> > >> reasons$gender<- ifelse(reasons$salutation== "Mr" & >> reasons$salutation== >> > >> "Father","Male", ifelse(reasons$salutation=="Mrs" & >> > reasons$salutation== >> > >> "Miss","Female",1)) >> > >> >> > >> Please suggest. >> > >> >> > >> [[alternative HTML version deleted]] >> > >> >> > >> ______________________________________________ >> > >> R-help@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.htmland provide commented, >> > >> minimal, self-contained, reproducible code. >> > > >> > > >> > > >> > > [[alternative HTML version deleted]] >> > > >> > > ______________________________________________ >> > > R-help@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@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/posti >> ng-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > [[alternative HTML version deleted]] ______________________________________________ R-help@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.