okay fixed it by putting "c" in quote marks.
1Rnwb wrote: > > Hello, I am using "B" as a vector to store all the t.tests. since i am a > newbie to both R and statistics I am not sure if "B" is the list. Also I > see "c" used in the do.call formula and do not know what it is being used > for. I used aggregate but getting this error" Error in > aggregate.data.frame(eo, eo$PlateID, function(.sub) t.test(ENA78 ~ : > 'by' must be a list". > As i mention in my OP that I am using is function from an earlier post. > any help is appreciated. > Thanks > Sharad > > > Jun Shen-3 wrote: >> >> I never used "by". Is "B" a list? If not, I am not sure if lapply can >> take >> it. Try aggregate(). >> >> On Fri, Aug 28, 2009 at 10:53 AM, 1Rnwb <sbpuro...@gmail.com> wrote: >> >>> >>> Hello list, >>> >>> I have a similar issue as this post >>> http://tolstoy.newcastle.edu.au/R/e6/help/09/04/11438.html#options2 and >>> I >>> used the suggestion provided by Jorge with modifications to my data >>> do.call(c,lapply(your_list_with_the_t_tests,function(x) x$p.value)) >>> >>> but I am getting the following error after excuting the code >>> >>> B<-by(eo,eo$PlateID, function(.sub) t.test(mcp1~Self_T1D,data=.sub, >>> na.rm=T)) #ttest platewise >>> do.call(c,lapply(B, function(x) x$p.value)) >>> Error in do.call(c, lapply(B, function(x) x$p.value)) : >>> 'what' must be a character string or a function >>> >>> here "B" is equal to "your_list_with_the_t_tests. is something i am >>> doing >>> wrong >>> > >>> -- >>> View this message in context: >>> http://www.nabble.com/extracting-pvalues-from-ttest-tp25192381p25192381.html >>> Sent from the R help mailing list archive at Nabble.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. >>> >> >> [[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. >> >> > > -- View this message in context: http://www.nabble.com/extracting-pvalues-from-ttest-tp25192381p25349826.html Sent from the R help mailing list archive at Nabble.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.