I had spent so many hours failing to find a line graph generator for my benchmark results that I just wanted to plug in. I tried quite a few like Google\'s chart API but it stil
I use gnuplot. It is not a lib, but a separate executable file. You can output plotting data to one file, and plotting commands in another - script file, which refer to data file. Then call gnuplot with this script file. Another way is to use qwt. It is a real library, but it depends on Qt. If you already use Qt in your project, it is very straigth way to plot graphs. If not, then just use gnuplot
You can use python mathplotlib, which generates beautiful graphs like:
(Source code)