Hi All, I've converted my merger tree code to use pydot, and it seems to work well. Using it I was able to remove quite a bit of code, and add the ability to write the output directly to an image format. Looking around the teragrid world, all machines have 'dot' in the default path, which means that graphviz is supported to some extent on the systems. I also built graphviz from source on Triton with no difficulty. This means that direct-to-image output should work most places. The default behavior is still to a text file, which will always work in the absence of graphviz. I'm not going to push my changes now, seeing as yt-2.0 is being released by Matt soon. Would John and Matt mind if I converted the FOF merger tree, too? Stephen Skory stephenskory@yahoo.com http://stephenskory.com/ 510.621.3687 (google voice)