I was at 360|Flex Indy in the session on the Axiis Data Visualization Framework presented by Tom Gonzales and Michael VanDaniker. Axiis is a framework built on top of degrafa that allows you to develop new and unique data visualizations that can go way beyond the simple column, bar, and pie charts available in the standard Adobe Flex charting libraries.
One of Tom’s first slides showed a Smith Chart. Tom mentioned jokingly that Axiis didn’t yet do something this complicated. For me sitting in the room, I was a bit taken aback. In my WCAP project, I have an open enhancement ticket from a customer asking for a smith chart visualization for transmission lines. They want to be able to click on a transmission line and view the directionality of the data on a smith chart. My original plan for accomplishing this ticket was to simply use an image for the smith chart background and draw my data on top of it. I must admit, I took Tom’s admission that Axiis couldn’t do a Smith chart as a throwing down of the gauntlet of sorts. I talked to him afterward to let him know I wanted to take on the challenge.
To date, I’ve only been working in Degrafa to get the basics of everything down. I’ll need to solicit Tom and Michael’s help in porting the work I’ve done over to Axiis and open-sourcing the code once I get a little further with it. So far, the most difficult part was calculating the arc angles and radii for each line on the smith chart based on the smith chart coordinates where the arc started and stopped. I still have a way to go in adding the various text labels along the curves as well as porting my work into a more reusable Axiis container.
The image above is the from-impedance(red) and to-impedance(blue) data across a 50 ohm transmission line with a sweep from 0.98mHz to 1.02mHz using a data point every 0.001mHz.
Hopefully, this little endeavor will benefit my WCAP customers as well as the open-source Flex community at the same time.