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 <shivipmp82 at 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.4567 at
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, <ruipbarradas at 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$salutation=="Miss".
> > > Try instead | (or), not & (and).
> > >
> > > Hope this helps,
> > >
> > > Rui Barradas
> > >
> > >
> > >
> > > Citando Shivi Bhatia <shivipmp82 at gmail.com>:
> > >
> > >> Dear Team,
> > >>
> > >> I need help with the below code in R:
> > >>
> > >> gender_rec<-
c('Dr','Father','Mr'=1,
'Miss','MS','Mrs'=2, 3)
> > >>
> > >> reasons$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$salutation=> > >>
"Miss","Female",1))
> > >>
> > >> Please suggest.
> > >>
> > >> [[alternative HTML version deleted]]
> > >>
> > >> ______________________________________________
> > >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and
more, see
> > >> https://stat.ethz.ch/mailman/listinfo/r-help
> > >> PLEASE do read the posting guide
> > >> http://www.R-project.org/posting-guide.htmland provide
commented,
> > >> minimal, self-contained, reproducible code.
> > >
> > >
> > >
> > > [[alternative HTML version deleted]]
> > >
> > > ______________________________________________
> > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more,
see
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide http://www.R-project.org/
> > posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible
code.
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/
> posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]
Thank you Jeremiah and all others for the assistance. This really helped. On Sat, Aug 6, 2016 at 5:01 AM, jeremiah rounds <roundsjeremiah at gmail.com> wrote:> Something like: > > d = data.frame(score = sample(1:10, 100, replace=TRUE)) > d$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 <shivipmp82 at 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.4567 at 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, <ruipbarradas at 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 <shivipmp82 at 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 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.htmland 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/posti >> ng-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > >[[alternative HTML version deleted]]
Hi, please also have a look at the 'cut' function.Very handa function for these types of situations. Best, Fredrik On Sun, Aug 7, 2016 at 8:10 PM, Shivi Bhatia <shivipmp82 at gmail.com> wrote:> Thank you Jeremiah and all others for the assistance. This really helped. > > On Sat, Aug 6, 2016 at 5:01 AM, jeremiah rounds <roundsjeremiah at 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 <shivipmp82 at 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.4567 at 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, <ruipbarradas at 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$salutation=="Miss". > >> > > Try instead | (or), not & (and). > >> > > > >> > > Hope this helps, > >> > > > >> > > Rui Barradas > >> > > > >> > > > >> > > > >> > > Citando Shivi Bhatia <shivipmp82 at gmail.com>: > >> > > > >> > >> Dear Team, > >> > >> > >> > >> I need help with the below code in R: > >> > >> > >> > >> gender_rec<- c('Dr','Father','Mr'=1, 'Miss','MS','Mrs'=2, 3) > >> > >> > >> > >> reasons$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 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.htmland 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/posti > >> ng-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. >-- "Life is like a trumpet - if you don't put anything into it, you don't get anything out of it." [[alternative HTML version deleted]]