# Custom units Compatible with Conversions [closed]

I am writing a Mathematica Palette to work with units, and am wondering if anyone knows a way to define new units outside of the standard ones that come with Mathematica 9. I do know of the IndependentUnit command

Quantity[3, IndependentUnit["Boxes"]]


which in this specific case makes sense to be non-convertible, but I want to add convertible units such as Smoots, Batmans, and MingDynasties. I found an old package that seemed to do this ("Automatic Units package"), but I couldn't get any of the functions to work, even when copied from the included documentation. What I want is to be able to convert from user-defined units to more conventional ones and back again without manually doing it, i.e

Unit[Smoots,67 Inches] (*defines 1 Smoot to be equal to 67 inches*)
UnitConvert[5 Smoots, Inches] (*would return 335 inches*)
UnitConvert[335 inches,Smoots] (*would return 5 Smoots*)


Since this has been done in a package before, I don't foresee this being impossible, but I am a fairly novice Mathematica Programmer, and could be very mistaken. If anyone has any insight, it would be very much appreciated.

• QuantityUnits is a complete rewrite of the AutomaticUnits package and has little in common with it, so the documentation examples are certainly not going to be compatible. To make matters difficult, the source code of QuantityUnits is encrypted. Bottom line, I think QuantityUnits has a fixed set of units that it can work with, and would need to look into how to circumventing this to define new ones. It requires downvalues to be defined on a number of different symbols to get it working. – Oleksandr R. May 9 '16 at 9:26
• Same question, essentially: (39006) – Oleksandr R. May 9 '16 at 9:31
• If any long-standing user of the site wants to have a try at implementing the custom unit, I have some information that may be valuable but which it isn't possible to give here. Email me: "1:eJxTTMoPCpZjYGDIz0nNLk7MSymKL0osLigtyczLL3OozE3MzNFLzs8FAAAzDfw=" – Oleksandr R. May 9 '16 at 9:35