Xypic not rendering edges

Question

First off, I'm rather new to LaTeX and use it in a limited fashion (typing up notes + problem sets for my math classes). As such I'd like to apologize in advance for not knowing the correct terminology or details to include.

Anyway, I'm trying to create a directed graph in using the XYpic package. My usual workflow for something like this is to use sample code from a tutorial and massage it until it does what I need to. I did that in this case, drawing from http://www.math.unm.edu/~loring/links/graph_s07/tex_graphs.pdf and the XYpic reference manual.

The sample bits I used complied without error, but the edges (the bits defined by "a"-"b" for example) simply weren't displayed in the pdf. I pulled the sample file wholesale from the third page of my first link and tried it in a new document and the same problem appeared.

So, I suppose my question is: how does one troubleshoot this sort of thing? It seems pretty clear that the problem is on my machine, but I'm not sufficiently versed in the inner workings of TeX to even know where to begin. Any advice would be greatly appreciated.

This is on a Mac, using the 2011 texlive distribution and texpad & texworks as editors.

Answer 1

The default setup in TeXShop is that when you give a latex command, it actually runs pdflatex to directly produce a pdf file. If you use pflatex on the latex files from tex-graphs.pdf, the edges don't appear (I forget why), but if you run plain old latex to produce a dvi file they do appear. You can then run dvipdf on that dvi file to get a pdf file in which the edges do appear.

You can tell TeXShop to automatically use plain old latex and ghostscript to produce your pdf file (so that you'll see the edges) by following the directions the AMS gives at http://www.ams.org/publications/authors/faq/author-faq (go to that site and enter texshop into the search box). E.g., one way is to go into the Typeset menu and select TeX and Ghostscript; it will then process your latex file that way until you exit from TeXShop. Alternatively, put the line

%!TEX TS-program = latex

into your latex file as the first line in the file.