kumpfjn writes "I recently have taken on a project where we have to produce plots for sensor readings. These line plots can be over several years meaning one sensor's line plot could consist of 50,000+ points. We have been using the GD graphing in PHP (also jpGraph) but it is still pretty slow when the final rendering occurs. I've done quite a bit of searching and so far (for PHP at least) my results have been lest than favorable. Everything I have found ends up performing the same or slower than GD. I also did quite a bit of testing of every piece of my code and the database and queries are very well optimized. The bottleneck is at the final generation of the image for display. My next step was to pursue tools in Python but I wanted to know what the expert community of Slashdot users are using and/or would recommend for this type of project. We are using Linux/Unix servers but otherwise are pretty open to whatever performs the best. These plots need to be generated on the fly based on parameters (date ranges, sensor combinations, etc) so running batch jobs to generate images and selecting them would not be favorable for us although this may be fall back."