I didn't mean to imply that was the only time that it was required, only that it's not universal in R.
On Sat, Aug 1, 2020 at 2:22 PM Bert Gunter <bgunter.4...@gmail.com> wrote: > ... yes, but so does lm() for a categorical **INdependent** variable with > more than 2 numerically labeled levels. n levels = (n-1) df for a > categorical covariate, but 1 for a continuous one (unless more complex > models are explicitly specified of course). As I said, the OP seems > confused about whether he is referring to the response or covariates. Or > maybe he just made the same typo I did. > > 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 Sat, Aug 1, 2020 at 11:15 AM Patrick (Malone Quantitative) < > mal...@malonequantitative.com> wrote: > >> No, R does not. glm() does in order to do logistic regression. >> >> On Sat, Aug 1, 2020 at 2:11 PM Paul Bernal <paulberna...@gmail.com> >> wrote: >> >>> Hi Bert, >>> >>> Thank you for the kind reply. >>> >>> But what if I don't turn the variable into a factor. Let's say that in >>> excel I just coded the variable as 1s and 0s and just imported the >>> dataset >>> into R and fitted the logistic regression without turning any categorical >>> variable or dummy variable into a factor? >>> >>> Does R requires every dummy variable to be treated as a factor? >>> >>> Best regards, >>> >>> Paul >>> >>> El sáb., 1 de agosto de 2020 12:59 p. m., Bert Gunter < >>> bgunter.4...@gmail.com> escribió: >>> >>> > x <- factor(0:1) >>> > x <- factor("yes","no") >>> > >>> > will produce identical results up to labeling. >>> > >>> > >>> > 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 Sat, Aug 1, 2020 at 10:40 AM Paul Bernal <paulberna...@gmail.com> >>> > wrote: >>> > >>> >> Dear friends, >>> >> >>> >> Hope you are doing great. I want to fit a logistic regression in R, >>> where >>> >> the dependent variable is the covid status (I used 1 for covid >>> positives, >>> >> and 0 for covid negatives), but when I ran the glm, R complains that I >>> >> should make the dependent variable a factor. >>> >> >>> >> What would be more advisable, to keep the dependent variable with 1s >>> and >>> >> 0s, or code it as yes/no and then make it a factor? >>> >> >>> >> Any guidance will be greatly appreciated, >>> >> >>> >> Best regards, >>> >> >>> >> Paul >>> >> >>> >> [[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/posting-guide.html >>> and provide commented, minimal, self-contained, reproducible code. >>> >> >> >> -- >> Patrick S. Malone, Ph.D., Malone Quantitative >> NEW Service Models: http://malonequantitative.com >> >> He/Him/His >> > -- Patrick S. Malone, Ph.D., Malone Quantitative NEW Service Models: http://malonequantitative.com He/Him/His [[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.