I was tasked with creating a demonstration of a dynamically generated graph for one of the grant proposals being worked on at present. This isn’t something we’ve really done before in PHP, but I had a feeling it would not be a unique requirement. A quick search revealed that a PEAR package exists for just this purpose: Image_Graph.

Installation was not too difficult, though I did have to ensure that a few dependencies were installed before PEAR would load the package. Documentation for the module is not that great, but there are a number of samples and a fairly active discussion forum. (There used to be a decent community, but the site appears to have gone under.)

I did not find the graphing object very intuitive. It seems to me that a lot of the properties and functions are abstracted from the objects they affect. I suspect this was a design decision to allow for greater flexibility, but it may also be due to an older coding style. The current branch appears to have been developed in earnest starting in 2005, and it’s been a few years since a new release. Even so, my initial exposure leads me to believe the package may be stable enough for even a production-level project so long as sufficient QA has been performed.

It took me only a couple of days to hack together the demonstration. Though the requirements of the script were few, I decided to push the limits of my object-oriented PHP and create the graphing component as a class. Overall it was a good first-try at producing something of this nature. You can find the demonstrator at http://flora.p2061.org/weather_data/.