R help - Apr 2023 - Should help of estimate in t.test be corrected?

Hi,

Not important, but IMHO the estimate component of the t.test holds an 
estimate of mean of each group, never a difference. The doc says 
"estimate??? the estimated mean or difference in means depending on 
whether it was a one-sample test or a two-sample test."

 > t.test(0:4)$estimate
mean of x
 ??????? 2
 > t.test(0:4, 5:9)$estimate
mean of x mean of y
 ??????? 2???????? 7

Best,
Samuel

Hi

You need to use paired option
> t.test(x=0:4, y=sample(5:9), paired=TRUE)$estimate
mean difference
             -5

Cheers
Petr
> -----Original Message-----
> From: R-help <r-help-bounces at r-project.org> On Behalf Of Samuel
Granjeaud
> IR/Inserm
> Sent: Sunday, April 2, 2023 11:39 PM
> To: r-help at r-project.org
> Subject: [R] Should help of estimate in t.test be corrected?
>
> Hi,
>
> Not important, but IMHO the estimate component of the t.test holds an
> estimate of mean of each group, never a difference. The doc says
> "estimate    the estimated mean or difference in means depending on
whether
> it
> was a one-sample test or a two-sample test."
>
>  > t.test(0:4)$estimate
> mean of x
>          2
>  > t.test(0:4, 5:9)$estimate
> mean of x mean of y
>          2         7
>
> Best,
> Samuel
>
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