R help - Feb 2017 - How to search t value when you know degree of freedom?

Hi everyone,

How to search t value when you know degree of freedom? 

For example, the degree of freedom is 29, how to use R to calculate the t value
for it?

t.test does not help, or pnorm? I am not sure.

Thanks.

Hello,

It would be ?pt not pnorm.
And as you can see in that help page you need another value, the value 
of the quantile. (Don't worry about the arguments ncp or log just q and df)

Hope this helps,

Rui Barradas

Em 22-02-2017 15:53, vod vos escreveu:
>
> Hi everyone,
>
> How to search t value when you know degree of freedom?
>
> For example, the degree of freedom is 29, how to use R to calculate the t
value for it?
>
> t.test does not help, or pnorm? I am not sure.
>
> Thanks.
>
> ______________________________________________
> 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.
>

If we want to get 95% limit of t value, the result will be

pt(0.975, 29)  =  2.045

is that right?


 ---- On ???, 22 ?? 2017 08:04:36 -0800 Rui Barradas <ruipbarradas at
sapo.pt> wrote ----
 > Hello, 
 >  
 > It would be ?pt not pnorm. 
 > And as you can see in that help page you need another value, the value  
 > of the quantile. (Don't worry about the arguments ncp or log just q
and df)
 >  
 > Hope this helps, 
 >  
 > Rui Barradas 
 >  
 > Em 22-02-2017 15:53, vod vos escreveu: 
 > > 
 > > Hi everyone, 
 > > 
 > > How to search t value when you know degree of freedom? 
 > > 
 > > For example, the degree of freedom is 29, how to use R to calculate
the t value for it?
 > > 
 > > t.test does not help, or pnorm? I am not sure. 
 > > 
 > > Thanks. 
 > > 
 > > ______________________________________________ 
 > > 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. 
 > > 
 >