search for: t_test

...5625 -117.0938 12.23 0.42 1.11 2.42 ALFI 19 USACE UC 48.15625 -117.0938 13.19 1.00 1.73 3.14 ALFI 20 USACE UC 48.15625 -117.0938 14.31 1.77 2.62 3.78 I am interested in running the t-test by the "Site" index. My code looks like this: t_test<-by(error, error['Site'], function(dat) t.test(subset(error $diff20),subset(error$diff80), data=dat)) This code runs the t-test, but over the whole dataset without discriminating by Site, so each Site's result is the same. Could someone help determine a better approach or why m...

...S3 methods are not consistent, because R does not recognize that the basic function name is "t.test" instead of "t": t: function(x) t.test.speclib: function(x, y, paired, ...) Is there any workaround or do I have to rename the t.test.speclib function to something like t_test.speclib? Thank you in advance Lukas [[alternative HTML version deleted]]

I am trying to do t-test to test whether the mean of one one column of the data frame is greater then another. please help me out. -- Arkajyoti Jana M. Phil/ 2nd semester Centre for Economic Studies and planning School of Social Sciences Jawaharlal Nehru University New Delhi-67 [[alternative HTML version deleted]]

What's the difference between t.test(x, y) and pairwise.t.test()? Is it just that the former takes two vectors, whereas the latter takes a vector and a factor?