[Xy-pic] Font scaling

[Michael Barr]

In connection with the question raised by Peter Selinger about getting 
thicker arrows at larger size, I have successfully used the following 
macro in connection with extarticle.cls that allows any base size from 8 
(I think) to 25 pt.

\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}

You use it in the form \fontscale#1, where #1 is one of h, 1, 2, 3, 4, 5 
for 11, 12, 14, 17, 20 or 25 pt, resp.

Michael Barr