[R] [FORGED] Dependent Variable in Logistic Regression

[Martin Maechler]

>>>>> Abby Spurdle 
>>>>>     on Sun, 2 Aug 2020 15:13:51 +1200 writes:

    > That's a bit harsh.  Isn't the best advice here, to post a
    > reproducible example...  Which I believe has been
    > mentioned.

    > Also, I'd strongly encourage people to use
    > package+function name, for this sort of thing.

    >     stats::glm

    > As there are many R functions for GLMs...

Sorry, Abby, I do disagree here ((strongly enough as to warrant
this reply) :

We're talking about doing "basic" statistics with R,  and these
function in the stats package have been part of R even before
got a version number.

So, no,  glm()  {and the stats package} are the default and I still
think everybody should know and assume that.

Martin

    > On Sun, Aug 2, 2020 at 12:47 PM Rolf Turner
    > <r.turner using auckland.ac.nz> wrote:
    >> 
    >> 
    >> On 2/08/20 5:39 am, Paul Bernal 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,
    >> 
    >> 
    >> There have been many responses to this post, the majority
    >> of them being confusing and off the point.
    >> 
    >> BOTTOM LINE: R/glm() does *NOT* complain that one "should
    >> make the dependent variable a factor".  This is bovine
    >> faecal output.
    >> 
    >> As Rui Barradas has pointed out (alternatively: RTFM!)
    >> when you fit a Bernoulli model using glm(), your
    >> response/dependent variable is allowed to be
    >> 
    >> * a numeric variable with values 0 or 1 * a logical
    >> variable * a factor with two levels
    >> 
    >> The OP presumably fed glm() a *character* vector with
    >> values "0" and "1".  Doing *this* will cause glm() to
    >> whinge.
    >> 
    >> I reiterate: RTFM!!!  (And perhaps learn to distinguish
    >> between character vectors and factors.)
    >> 
    >> cheers,
    >> 
    >> Rolf Turner
    >> 
    >> --
    >> Honorary Research Fellow Department of Statistics
    >> University of Auckland Phone: +64-9-373-7599 ext. 88276
    >> 
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    > ______________________________________________
    > R-help using 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.