Friday, October 5, 2007

Django-rendertext 0.2 and a new jquery plot plugin

A quick update. I've released django-rendertext 0.2. The most notable change is support for GIF output, mostly intended for the browser that didn't support PNGs properly until very recently.

I deliberately built rendertext with PNGs first because it's the format of the future. IE7 usage is picking up (see for instance here or here), within a year or two it's probably completely dominant among IE users. Now that I whipped up the GIF support, I'm glad I didn't start with it because it was a real PITA to do with PIL (Python Imaging Library). PIL doesn't have proper documentation of the corner cases that turn out to be the most important and only sketchy support for palettes.

I've also been working on a plotting plugin for jQuery. We've not been entirely satisfied with Plotr which otherwise appeared to be the prettiest and most advanced Javascript-only plotting library out there. It's for Prototype and not for jQuery but most importantly I've found it confusing to hack on. And it's completely missing the interactive aspects.

So I have started my own project. So far I think I've discovered that the hardest part of a library for plotting is not actually drawing the stuff, but layouting and auto-adjusting the axes. In any case, in two days I've gotten pretty far. Here's a screenshot (click to get the full version):

What's missing right now is support for plotting points and columns, options for controlling the plot, legends, support for time and the interactive stuff such as zooming, highlighting graphs, tooltips for points on mouse hover. Also, the auto-adjusting algorithm is still a bit rough but I think I managed to crack it on paper last night so I just need to implement and test it.

In other news, from Werner Vogels' blog here's how Amazon manages storage (warning! scientific paper ahead). Now that's as far as you can get from N=1 thinking. As an aside, I'm fond of that guy's name, Werner Vogels (note for English native speakers: in German the surname is pronounced like [fogels] not [wogels]). It's just like der Vogelfänger bin ich ja I guess, nice rhythm.

1 comment:

  1. "the hardest part of a library for plotting is not actually drawing the stuff, but layouting and auto-adjusting the axes"
    I had exactly the same experience back in 1985!

    Jens K. Laursen