Charting and Graphing

You might remember my last post about the Gentoo Portage size which contained some pie charts showing the proportion of space used by the various pieces that make up Portage itself.

On a related note, yes I know that pie charts are often the wrong tool; I still think that for the use case of that post, the pie chart was the best option because I only had to give proportions and not a comparison; as you’ll see though, I’m going to use it sparingly.

Finding a decent way to plot the charts has always been a problem for me, since I would have wanted more than once to give some graphical representation of improvements and benchmarks, but the tools available all have their own set of quirks, which means that I have to fight with them a lot more than I can afford myself to:

• gnuplot (which, by the way, does not make pie charts at all), is tremendously complex, to the point that even the quite good book about it does not help to easily make use of it, if you’re not already an expert in statistical analysis;
• R, if anything, is even worse, to the point I don’t really want to discuss it!
• using gruff should allow to draw all the needed chart, given you can easily represent the values in Ruby; unfortunately it doesn’t really work extremely well, and more than once, both for pie charts and bar charts, I found the colours not to properly cover one the other, with quite shitty results;
• using Google Docs, with the spreadsheet component, looked almost good, if it wasn’t for the fact that lots of people have had trouble loading the charts in my previous post; while the Google application is definitely well-designed, especially for what concerns user interface and basic functionalities (just as an example, the ability to move the graph to its own dedicated sheet, which I remember being available on Microsoft Excel 97, is not available in OpenOffice, while it is present in Google’s spreadsheet), it also lacks some more “public” features: there is no way to ask for the graphs of a given size when exporting (for instance for thumbnails), and at the same time, the auto-generated text in the public, exported chart seems to always be in the locale the generating interface was set in… guess what? I have it in Italian;
• I ended up reconsidering OpenOffice; it worked great with flowcharts so I wanted to see the good “old” suite at work to do something that it should probably be designed for.

Now, since I’m not sure whether I’ll post this before or after the results (I’m writing it before the results’ post, but that’s not to say much to be honest, since I have a queue of posts already written, as usual), I cannot really say much about the results themselves, but my area of analysis this time has been the distribution of sizes and overhead with different block sizes (as suggested by Robin). I used Ruby to gather the data, and I’ve copied it into a large sheet into Calc (reaching column AL) — incidentally, the amount of data to handle is the reason why I didn’t go with Google Docs this time: with Firefox is definitely too slow to work with it; probably it’s designed to be faster with Chrome. Then it was time to condition the data…

OpenOffice definitely have some usability issues in that matter! First of all, when selecting the range of data to plot, there is no easy way to select non-contiguous columns, since once you release the mouse button the interface returns to the chart wizard. The trick is to choose the columns manually, using the form A1:A8,C1:C8 and so on so forth. I used again Ruby to generate the list of columns for me or it was definitely a mess… I gave up when I had to re-do the graph for the third time because I didn’t select some stuff, so I just used another sheet to copy the information I needed, and then filter out what I wouldn’t be needing.

As I noted above, there is no way, that I could find or Google, to create a sheet that only holds a chart. I’m pretty sure that Microsoft Excel 97 had a feature like that… and I’m definitely certain it has it in version 2007 (because I have a fully licensed Office 2007 here). Google Docs, as I said, has it as well. The reason why I’m upset that it lacks that feature, is because it would have made it quite a lot easier to export the charts for publication; instead the only way I found was to copy the chart, and then paste it in a Draw document: at that point, while the chart was still tweakable to reorder columns and stuff like that, I had to re-tweak it every time I noticed a flaw in the data, since it was disconnected from its original data source.

Another area that OpenOffice definitely got to improve is the handling of colours: everywhere you select colours you’re not allowed to freely select one, you have to add it to the OOo palette first… which in turn requires a restart of OOo itself since sometimes it fails to pick it up in all the instances. This might not be such a huge deal when seen by most users who just need “a” colour, but it really is upsetting when you know exactly which colour you want. And indeed it reduces the usability of Draw: for a word processor or a spreadsheet, precise colours might not be that important, but for software like Draw (or Impress), the ability of choosing an arbitrary colour without having to jump through a long series of hoops is definitely important!

This is definitely something that sometimes upsets me: OpenOffice has almost all the cards ready to be a perfect poker of productivity software, but there are is a number, toward infinity, of details that need to be fixed up (just to add another quickly: the fact that the packages, ebuilds included, don’t install the templates by default, and you got to install them from the Sun extensions site, which by the way installs them in your home directory and I don’t really like that). I really hope that this is going to get fixed in the future, but counting in the go-oo split there is really a lot of mess around OpenOffice, like a lot of other huge projects (OpenJDK/IcedTea, Mozilla/IceCat/IceWeasel, …). Why Free Software developers can’t really get along together for more than their own itches?