To use the pretty graphs you have to first build/run the ltmtest from the root directory of the package. Todo this type
make timing ; ltmtest
in the root. It will run for a while [about ten minutes on most PCs] and produce a series of .log files in logs/.
After doing that run "gnuplot graphs.dem" to make the PNGs. If you managed todo that all so far just open index.html to view them all :-)
Have fun
Tom