Web data visualization/charting library

I'm building a Rails app that needs some data visualization. What is a good library to learn? (If it matters, I don't have much web/javascript experience, but I'm starting to learn.)

I've been dabbling around with Protovis... But, well, I don't understand what all the hype is. It seems quite long and painful even to create just a simple bar chart with axes, and badly in need of d开发者_Python百科efaults! [But the only other real graphics library I've used is ggplot2 in R, so maybe this is standard for the web?]

I've seen gRaphael suggested, and the single piece example code I've seen on the website [for a piechart] makes it look much easier to use than Protovis. But there's no documentation, so I don't know how to learn to use it.

I've played a bit with the Google Charts API in the past, and it's fairly easy to use and well-documented, so maybe I should just stick with that if I don't need anything super fancy and customized?

So, I guess: what are the advantages/disadvantages of Protovis/gRaphael/Google Charts? Are there any other data visualization libraries I should be considering?

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Check out Ryan Bates screencast on charts. It is focused on Highcharts, but he also shows other alternatives.

http://railscasts.com/episodes/223-charts

I have only used Google Charts, but I was considering trying some of these after watching this screencast a few months ago. Hopefully this will show you a few more options that may suit you.

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You can give Gruff a try. The graphs look nice and the API is quite easy to use. http://nubyonrails.com/pages/gruff

Hoa