search for: multidimension

I don't find rbind, cbind or other bind that bind in other dimesions for multidimension array while keeping the result of the same dimension. For example, say, dim(x)=c(2,3,4), dim(y)=c(3,3,4). I want to have the result z, where dim(z)=c(2+3,3,4), when I bind x and y in the first dimenion. The bind can also be in the 2nd and 3rd dimesion. Could somebody let me know if this family of...

...the test for equality of their covariance matrices and mean vectors. Normally these tests should be done by chi square test (box provided) and Hotelling's T square test respectively. Which R functions could do this kind of test? I just find some functions could do for one dimension, but no for multidimension. Some one suggests bartlett.test, but it seems just works for one dimension. Do you know which ones could do that, or I have to do R programming by myself? Thank you, Shengzhe