Dear all Just for fun, I have just downloaded the paper mentioned below and checked it with R-1.6.1. Everything is ok with exception of Table 2b, where I get always 1 instead of 0.5: > pbinom(1e15,2e15,0.5) [1] 1
Which value should be correct? Best regards Christian Stratowa ============================================== Christian Stratowa, PhD Boehringer Ingelheim Austria Dept NCE Lead Discovery - Bioinformatics Dr. Boehringergasse 5-11 A-1121 Vienna, Austria Tel.: ++43-1-80105-2470 Fax: ++43-1-80105-2683 email: [EMAIL PROTECTED] > -------- Original Message -------- > Subject: Re: [S] Exact p-values > Date: Thu, 13 Feb 2003 18:31:38 +0100 > From: "Rau, Roland" <[EMAIL PROTECTED]> > To: 'Spencer Graves' <[EMAIL PROTECTED]>, Jose Mar�a Fedriani > Laffitte <[EMAIL PROTECTED]> > CC: [EMAIL PROTECTED] > > Dear all, > > in relation to your question, the following working paper of Leo Knuesel, > University of Munich, might be of interest: > "On the Accuracy of Statistical Distributions in S-Plus for Windows > (1999)" > You can download the paper from (pdf-Format, 45k): > http://www.stat.uni-muenchen.de/~knuesel/elv/accuracy.html > > Best, > Roland > > > -----Original Message----- > > From: Spencer Graves [SMTP:[EMAIL PROTECTED]] > > Sent: Thursday, February 13, 2003 6:12 PM > > To: Jose Mar�a Fedriani Laffitte > > Cc: [EMAIL PROTECTED] > > Subject: Re: [S] Exact p-values > > > > > > Try ( 1-pchisq(29.8, df=1)): With S-Plus 6.1, I got 4.78992e-008. > > > > By the way, the distribtion functions in R have more > arguments. > > For example, pchisq(29.8, df=1, lower.tail=F) produces the same > > answer, and pchisq(29.8, df=1, lower.tail=F, log=T) produces its > natural > > logarithm. Also, pchisq, dchisq, qchisq, and rchisq in R all have an > > "ncp" noncentrality parameter argument; only pchisq has such in S-Plus > > 6.1. Similarly, none of the Student's t functions in S-Plus have a > > non-centralitity parameter; in R, pt has an argument ncp, and from > this > > one can easily program ncp for dt, qt and rt. Also, the distribution > > functions in the current release of S-Plus are known to have problems. > > For example, pt(-1, Inf) = 0.5 in S-Plus 6.1, but 0.159 in R; > clearly, > > S-Plus gives a wrong answer without warning. > > > > Best Wishes, > > Spencer Graves > > > > Jose Mar�a Fedriani Laffitte wrote: > > > > >Dear all, > > > > > > I want to get the exact p-values, on 1 degree of freedom, for an > > array > > >of chi-square values. When my chi-square values are equal or lower > than > > >29.7, I get the exact associated p-values. Thus, for instance: > > > > > > > > > > > >>pchisq(29.7, df=1) > > >> > > >> > > >[1] 0.9999999 > > > > > >However, when my chi-square values are greater or equal to 29.8 what I > > get > > >is: > > > > > > > > > > > >>pchisq(29.8, df=1) > > >> > > >> > > >[1] 1 > > > > > > > > > Could anyone tell me how to fix this trivial issue? Very > grateful, > > Jose > > >M. Fedriani > > > > > >**************************************** > > >Jose M� Fedriani Laffitte > > >Estacion Biologica de Donana (CSIC) > > >Avda. M� Luisa s/n > > >41013-Sevilla > > >Spain > > >Tel. +34-954232340 > > >Fax +34-954621125 > > >http://ebd.csic.es > > > > > >-------------------------------------------------------------------- > > >This message was distributed by [EMAIL PROTECTED] To > > >...(s-news-request clipped)... > > > > > > > > > > > > -------------------------------------------------------------------- > > This message was distributed by [EMAIL PROTECTED] To > > ...(s-news-request clipped)... > -------------------------------------------------------------------- > This message was distributed by [EMAIL PROTECTED] To > ...(s-news-request clipped)... > > ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help
