The data have no resemblance to what prop.trend.test expects (counts and totals, optionally group scores).
The prop.trend.test() function tests for trend in proportions. Were you attempting a rank correlation, or maybe a rank sum (Wilcoxon type) test against a directional alternative? (I'm not too sure, but package "coin" might have the latter). -pd On 15 Jan 2014, at 07:30 , Keniajin Wambui <kiang...@gmail.com> wrote: > I am using R3.02 on WIndows 7 64bit. > How can I test for trend across ordered groups. I am using > `prop.trend.test` but it doesn't order into groups and doesn't give > the expected output of `sum of ranks` , `z value`... > > I have this data set and am doing > > `prop.trend.test (birthweight2$lbw2 ,birthweight2$gestwkgp2 )` > > Here is a sample data > lbw2 gestwkgp > normal birth weight 3 > normal birth weight 3 > normal birth weight 3 > normal birth weight 4 > normal birth weight 3 > normal birth weight 3 > normal birth weight 3 > normal birth weight 4 > low birth weight 2 > normal birth weight 4 > > > > > -- > Mega Six Solutions > Web Designer and Research Consultant > > ______________________________________________ > 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. -- Peter Dalgaard, Professor Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.
