[OS X TeX] xy-pic problems

[Roger Hart]

I've been trying to use xy-pic to draw some diagrams and have had two 
major troubles which I've been unable to solve: 1) the arrows it draws 
are jagged, very noticeably so in printouts; 2) resizing does not work 
properly, resulting in arrows missing their intended targets.

Specifically, I just want to draw a diagram showing the order of the 
multiplication of entries in a 3x3 determinant, so I wrote:

\[
\xymatrix {
  a_{11} \ar@{->}'[dr][ddrr] & a_{12} \ar@{->}'[dr][ddrr] & a_{13} 
\ar@{->}'[dr][ddrr] & a_{11} & a_{12} \\
  a_{21} & a_{22} & a_{23} & a_{21} \\
  a_{31} \ar@{->}'[ur][uurr] & a_{32} \ar@{->}'[ur][uurr] & a_{33} 
\ar@{->}'[ur][uurr] & a_{31} & a_{32} \\
}
\]

I also want to show the order of multiplication in an ancient Chinese 
mathematical treatise,

\[
\fbox{
  \xymatrix {
  &&&&&&&\\
  &| & & & & || & \\
  & & & & ||| ~ & | & \\
  & & & |||| \ar[dl]_{(i)~4-1=3} & | & & \\
  & & ||||| \ar[dl]_{(ii)~(3 \times 5) + 1 = 16} & | & & & \\
  & \overline{~|~}
  \ar `dl^r[0,5]_-{(iii)~(16 \times 6) - 1 = 95} `^u[0,5] `^u[0,5] 
`^dl[-4,4] [-4,4]_{(iv)~(95 \times 2) + 1 = 191}
  & | & & & &\\
&&&&&& &\\
}
}
\]

Unfortunately, the arrows are jagged.  And because xy-pic is designed 
more for commutative diagrams than the matrices I wish to draw, I need 
to reduce their size, and I've tried all sorts of arguments and values 
to try to get the arrows to look nice, such as,

@! @R=6pt @C=6pt @M=0pt @H=0pt @W=0pt

but have been unable to get straight arrows at any size.  And when I 
use various parameters above, the arrows fail to connect to their 
targets.

I'm not sure what I'm doing wrong, and obviously, I'm not much of an 
expert on xy-pic.  I'd very much appreciate any suggestions.

Thanks very much,

Roger

********************************

Roger Hart
Assistant Professor, Departments of History and Asian Studies
University of Texas at Austin

email: rhart at mail.utexas.edu
http://uts.cc.utexas.edu/~rhart

*********************************

--------------------- Info ---------------------
Mac-TeX Website: http://www.esm.psu.edu/mac-tex/
           & FAQ: http://latex.yauh.de/faq/
TeX FAQ: http://www.tex.ac.uk/faq
List Post: <mailto:MacOSX-TeX at email.esm.psu.edu>