Does anybody has a function or idea how to calculate qt with a noncentrality parameter? I'm porting a SAS-macro for equivalence (Wellek, 1994 TT2ST) to R and it seems that I need this to calculate tinv (SAS-command, I hope that this is R's qt,...I get the SAS-macro manual next week). thanks Peter -- P.Malewski, Limmerstr.47, 30451 Hannover, 0511-2135008 At work: http://www.MH-Hannover.de 0511 532 3194 / Fax: 0511 532 3190, P.Malewski at tu-bs.de, peter.malewski at gmx.de, malewski.peter at mh-hannover.de. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Peter Malewski <peter.malewski at gmx.de> writes:> Does anybody has a function or idea how to calculate qt with a noncentrality > parameter? I'm porting a SAS-macro for equivalence (Wellek, 1994 TT2ST) to R > and it seems that I need this to calculate tinv (SAS-command, I hope that > this is R's qt,...I get the SAS-macro manual next week).The easiest way is probably to use something like uniroot(function(x)pt(x, df, ncp) - p, c(-1e7,1e7)) It's not going to be fast, but if you just need one of them... (Look inside power.t.test for variations on the theme) -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._