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. > > >
Michael Dewey
2017-Feb-23 12:18 UTC
[R] How to search t value when you know degree of freedom?
When I do pt(0.975, 29) I do not get 2.045 so I think you must have declared a new function pt which is interfering with things. On 23/02/2017 10:40, vod vos wrote:> 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. > > > > > > > ______________________________________________ > 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. >-- Michael http://www.dewey.myzen.co.uk/home.html
David L Carlson
2017-Feb-23 13:06 UTC
[R] How to search t value when you know degree of freedom?
Perhaps a typo? It should be qt() not pt():> pt(0.975, 29)[1] 0.8311882> qt(0.975, 29)[1] 2.04523 ------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Michael Dewey Sent: Thursday, February 23, 2017 6:18 AM To: vod vos <vodvos at zoho.com>; Rui Barradas <ruipbarradas at sapo.pt> Cc: R-help at r-project.org Subject: Re: [R] How to search t value when you know degree of freedom? When I do pt(0.975, 29) I do not get 2.045 so I think you must have declared a new function pt which is interfering with things. On 23/02/2017 10:40, vod vos wrote:> 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. > > > > > > > ______________________________________________ > 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. >-- Michael http://www.dewey.myzen.co.uk/home.html ______________________________________________ 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.