[Xy-pic] Re: Thicker arrows

[Michael Barr]

I have successfully used the following (in conjunction with 
extarticle.cls) to produce transparencies at 17 and 20 points.  \ul stands 
for unitlength,  which I have set quite small (I forget what the default 
value is, but it shouldn't be hard to find in the xypic code).  You set 
\fontscale #1, where #1 = h,1,2,3, or 4 in conjunction with choosing the 
11,12,14,17, or 20pt option of extarticle and it works.  Of course, if you 
want only the lines thickened, I guess
\font\xydashfont=xydash10 scaled \magstep 3
(say), would thinken them by a factor of 1.7.  But what is below works for 
transparencies.

\catcode`\@=11
\ul=.01em%
\X at xbase =.01em%
\Y at ybase =.01em%
\def\scalefactor#1{\ul=#1\ul \X at xbase=#1\X at xbase \Y at ybase=#1\Y at ybase}%
\catcode`\@=12%

\def\fontscale#1{%
\if#1h\relax
\font\xydashfont=xydash10 scaled \magstephalf
\font\xyatipfont=xyatip10 scaled \magstephalf
\font\xybtipfont=xybtip10 scaled \magstephalf
\font\xybsqlfont=xybsql10 scaled \magstephalf
\font\xycircfont=xycirc10 scaled \magstephalf
\else
\font\xydashfont=xydash10 scaled \magstep#1%
\font\xyatipfont=xyatip10 scaled \magstep#1%
\font\xybtipfont=xybtip10 scaled \magstep#1%
\font\xybsqlfont=xybsql10 scaled \magstep#1%
\font\xycircfont=xycirc10 scaled \magstep#1%
\fi}

Michael Barr