[Jprogramming] "Gluing" rows together

[PackRat PackRat]

I do a lot of manipulations with stock market data and such (i.e.,
tabular data), and I often have to "rip apart" a table and then
reassemble the rows again.  The ripping apart is easy, but I've always
been challenged when putting it back together because the result never
came out the way I wanted (or expected).  After much experimenting and
mucking around, I came up with this (as an example):

    z=. (((a0 ,: a1) , a2) , a3) , a4    NB. "glue" rows together

However, there always seems to be a better way to do things in J.  Can
anyone enlighten me with an improved explicit manner (NOT tacit) of
doing this?  Thanks in advance!


Harvey