You are writing some code to with the goal of making a visual for the electric field produced from a single charge. As part of the calculation, you need to define a separation vector between the charge and the location at which you will display the electric field. The location at which you'll display the field you've already defined as r$\_$obs in the code. The charge has been defined with this line of code:

charge $=$ sphere$($pos$=$vec$(3,2,0),$ radius$=1\mathrm{.}5,$ color$=$color.red$)$

How can you define the separation vector in your code?