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 <sbpurohit@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
> >
> --
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> http://www.nabble.com/extracting-pvalues-from-ttest-tp25192381p25192381.html
> Sent from the R help mailing list archive at Nabble.com.
>
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