tungwaiyip.info

home

about me

links

Blog

< February 2010 >
SuMoTuWeThFrSa
  1 2 3 4 5 6
7 8 910111213
14151617181920
21222324252627
28      

past articles »

Click for San Francisco, California Forecast

San Francisco, USA

 

Visualization Using Variable Width Bar Chart

I was plotting a chart to visualize various development project in my area. The primary concern is in development density. But the project footprint itself is also a factor. We want to focus on big project that matters. We also want to identify outliers that has very high or very low density, but otherwise has small overall size and less relevance.

My solution is to use a variable with bar chart below. The height of each bar represents the density. The width represents the lot size. The area of each rectangle bar reflects the total number of units. The full article is posted in Potrero Boosters Neighborhood Association's website.

potrero condo density

I thought everything that worth inventing has been invented. So I was frustrated that I cannot find a tool to generate this chart. Nothing in Excel (that I know) can generate a chart like this. I end up turning to matplotlib. But even matplotlib does not seem to have a function that support this directly. Fortunately a small twist to its histogram function does the job for me. See my (unpolished) source code here. In any case working with matplotlib is fun and the quality of the chart is excellent.

2010.02.26 [, ] - comments

 

 

blog comments powered by Disqus

Made with PyBlosxom