Thank you for your response. I understand that different visualizations have different purposes and are intended for different media. Your radial chart is probably good for a poster, because it does attract attention. But even viewing it on a large monitor (larger tha A1), I found the labels difficult to read. The radial nature of the bars makes it very hard to compare results which are separated by more than a few degrees. For example, how does the dip in December 2001 compare to the peak of November 2000? Did it drop to 50% of the peak? 75%? It’s somewhere in that vicinity

I would like to take a stab at a reader-friendly form of your chart, as I often do as fodder for my own blog. In fact, I intended to do just that when I first saw it, but I do not have the data at hand, and the thought of manually digitizing it scared me away. If you care to forward me your data, I’ll put something together and share it with you.

Thank you for your opinion. Of course I don’t agree with everything you’ve said but I do agree with some. It does take a lot of space, but even that is relative, isn’t it? I made this to be a poster, say printed in A1 so the type would be 14pt. But if it was to be used on a magazine, then it would be ilegible.
A straighforward line chart would be better to show every thing you’ve stated, but if you wanted to add the main events that affected the changes in prices, and if you wanted to had this events in days, and wanted to show the last 10 years…

Well, the way I’ve found to show all that data (and not only the change of prices) was with this chart – with all it’s faults (and it has some). I would really love to see how you would pick the data in this chart and make it like you’ve said. Please send me your solution and I’ll be more then happy to post it (yes, that is the goal of whatype to have diferent views for the same problem).

Once again, thank you so much for your reply and comment. Looking forward to ear from you and to see your solution.

All the best
Pedro Monteiro

The Economist published a similarly misguided chart, which I deconstructed in Spiraling Down the Drain. At least in the Economist chart, there is a natural cycle in the 12 months of a year.