🚀 go-pugleaf

In article <9985180@MVB.SAIC.COM> DL24794%UAFSYSB.BITNET@SHSU.edu (Daniel H. Luecking) writes:

   > From: mclean@math.tamu.edu (Robert Mclean)
.......
   > Unfortunately, this produces:
   >
   >         (        )
   >         (        )
   >         (        )
   > (x,y,z) (a1,a2,a3)
   >         (a4,a5,a6)
   >         (a7,a8,a9)
   >
   > Aack! Any suggestions.
   >

   Yes. The problem is that the delimiters are constructed to be
   symmetric above and below the math axis. Putting the array in a
   \vtop  causes the math axis of the whole matrix to be in the top
   row.  This is correct for aligning the two matrices at their
   top rows, but not for the variable delimiters.

   The following macro works by putting the array in a  \vtop, then
   unboxing it into a  \vcenter  with the parenthesis and spacing
   added.  This is done inside math mode with  \displaystyle  set,
   inside an  \hbox  inside a  \vbox  to the height of the original
   \vtop. This worked in simple examples, but can probably be
   defeated by more complicated ones.  Two successive  \tpmatrix's
   will align at their first rows.

......
[plain tex macro deleted]

LaTeX users can get matrices with any kind of delimiters aligned at
the top or bottom by going

\begin{array}[t]({...})   %  ( ) aligned on top row

\begin{array}[b]\{{...}\}   %  { } aligned on bottom row

etc

This mechanism is defined in delarray.sty part of Frank Mittelbach's
ARRAY package. available from all good servers. (Frank isn't to blame
for delarray.sty though :-)

David

PS: if you are using my newarray.sty, which used to offer this feature,
please throw it array, and get the new ARRAY package instead.
--
                           David Carlisle
                                    JANET: carlisle@uk.ac.man.cs

                                    Computer Science Department
                                    Manchester University
                                    Oxford Road
                                    Manchester
                                    England
                                    M13 9PL