Sent from my iPhone
> On Jan 19, 2025, at 1:57?PM, David Winsemius <dwinsemius at
comcast.net> wrote:
>
> ?I don?t understand why you don?t include the full text of the error.
>
> ?
> David
> Sent from my iPhone
>
>> On Jan 19, 2025, at 10:00?AM, Sparks, John via R-help <r-help at
r-project.org> wrote:
>>
>> ?Hello R-Helpers,
>>
>> I was looking into how to test whether the beta coefficient from a
regression would be the same for two different groups contained in the dataset
for the regression.
>>
>> When I put that question into google, AI returned a very nice looking
answer (and a couple of variations on it).
>>
>> library(car)
>> data <- data.frame(income = c(30, 45, 50, 25, 60, 55),
>> education = c(12, 16, 14, 10, 18, 16),
>> gender = c("Male", "Female",
"Male", "Female", "Male", "Female"))
>> model <- lm(income ~ education * gender, data = data)
>> # Test if the beta for "education" is significantly different
between genders
>> test <- linearHypothesis(model, "genderMale - genderFemale =
0")
That last line appears unlikely to be parsed correctly. In R a ?=? sign is
interpreted as assignment whereas a ?==? (doubled equals) is a logical operator.
Since I?ve only got a iPhone at hand I can?t test. In the future you should
include full text of errors, preferably in the context in which they are
returned.
As an experiment I asked ChatGPT your question an it suggested
library(car)
data <- data.frame(
income = c(30, 45, 50, 25, 60, 55),
education = c(12, 16, 14, 10, 18, 16),
gender = c("Male", "Female", "Male",
"Female", "Male", "Female")
)
model <- lm(income ~ education * gender, data = data)
# Test if the effect of education differs by gender
test <- linearHypothesis(model, "education:genderMale = 0")
But I have the same concern about that code as I had with whatever your AI
produced.
?
David
>> print(test)
>>
>> This, however, produces an error that I can't find a way to
resolve.
>>
>> Can this test actually be done in this manner, or is this a case of AI
run amok.
>>
>> Guidance would be appreciated.
>> --John Sparks
>>
>>
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> PLEASE do read the posting guide
https://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> 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
https://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.