Automated Fibonacci Fan

Sorry to disappoint you but that will not be possible if your goal is to build this for Thinkorswim. And even it if were possible to build on Thinkorswim, it's light years beyond the scope of solutions I provide free of charge in the Q&A Forum.

I will provide a bit more detail because this post is going to be seen by a large number of our viewers:

1. The current version of Thinkorswim does not provide any language tools for creating, or modifying drawing objects. Which means we cannot use a scripting solution to place any drawing object on the chart, nor can we change it's parameters or properties from within any script
2. It may be possible to mash together a very rudimentary facsimile of a Fibonacci Fan on Thinkorswim. Emphasize the phrase "may be possible". Do you know how the lines of this drawing tool are computed? I don't, but I can tell you that math is only the very first step. So until you know how to compute one of these in a spreadsheet you don't have the first specification required to perform the first step.

The scripting language in Thinkorswim is very limited and lacks essential data objects which most programmers would consider absolutely essential to complete this request. So if this type of tool is essential to the success of your trading I suggest you start looking for existing solutions which have already been built for the more advanced trading platforms. Something like TradeStation, Sierra Chart, or NinjaTrader would be my first places to search.