[Xy-pic] uniform (but different) row and column spacing (fwd)

[Les Saper]

According to the Xy-Pic reference manual, the code @!R=<dimen> should give 
uniform row spacing by pretending that all entries have height and width 
<dimen> (of course only the height matters here).  Likewise @!C=<dimen> should 
affect column spacing.  Thus it should not matter in which order the two codes 
are given.

Consider the following two xymatrices (the code @=0pt means there will be no 
extra space between columns and rows):

\xymatrix @=0pt @!R=1cm @!C=1.5cm {
{\bullet} & {\bullet} \\ {\bullet} & {\bullet}}

\xymatrix @=0pt @!C=1.5cm @!R=1cm {
{\bullet} & {\bullet} \\ {\bullet} & {\bullet}}

They should produce identical non-square rectangles of dots, 1.5cm x 1cm. 
Instead each produces a square of dots, the first one 1.5cm x 1.5cm and the 
second one 1cm x 1cm.  What appears to be happening is that the second of the 
two codes is overring the first and it is applying to _both_ columns and rows.

Is this a bug?  Or have I misinterpreted the documention? If the latter, can 
someone suggest how to accomplish what I want?  (Note that I need to have the 
entries retain their true sizes to have arrows begin and end at the right 
places, so @R=1cm @C=1.5cm @!0 is not an option.)

Thanks,

Les Saper

-----------------------------------------------------------
Leslie Saper                    e-mail: saper at math.duke.edu
Department of Mathematics       phone: 919-660-2843
Duke University                 Fax: 919-660-2821
Box 90320
Durham, NC   27708-0320
USA