Do you mean to deal with the situation where you're doing many t-tests in a loop? If so there was a post very recently on this list about this:
https://stat.ethz.ch/pipermail/r-help/2008-February/153254.html Richard. Ng Stanley wrote: > Thanks. Someone please help to make t.test go through all the data and not > to be disrupted by the two problems. > > On 2/12/08, Petr PIKAL <[EMAIL PROTECTED]> wrote: > >> Hi >> >> [EMAIL PROTECTED] napsal dne 12.02.2008 09:09:23: >> >> >>> Hi, >>> >>> First problem: >>> >>>> test <- matrix(c(1,1,2,1), 2,2) >>>> apply(test, 1, function(x) { t.test(x) $p.value }) >>>> >>> Error in t.test.default(x) : data are essentially constant >>> >> make your data not constant >> >> >>> Second problem: >>> >>>> test <- matrix(c(1,0,NA,1), 2,2) >>>> apply(test, 1, function(x) { t.test(x) $p.value }) >>>> >>> Error in t.test.default(x) : not enough 'x' observations >>> >> increase number of observations >> >> >> >>> How to make t-test ignores this errors ? >>> >> Well, the procedure is complaining that you do not give it correct data. >> You shall be gratefull for a great software which prevent you from making >> silly things as try to compute t.test when data have zero variantion or >> number of observations is 1. >> >> Regards >> Petr >> >> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list >>> 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. >>> >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > 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@r-project.org mailing list 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.
