OpenMDAO/OpenMDAO-Framework — Issue #803: Abbreviated units are dangerous
Author: ssalonen
Created: 2012-01-30 17:29:01+00:00
State: open

Overall, I'm very pleased with the units module. There is one thing bothering me, however.

Short hand unit names are convenient when the context is known but they are quite often ambiguous when it comes to interpretation without a context (like in a computer program). For example, "ton" currently refers to 2000lb while some of us might think it refers to metric ton. Same kind of confusion is present with horse power (see varying definitions in wikipedia).

Also, as a related note, nautical mile, currently available as "nmi" is also generally known with "NM" (see wikipedia). Unlike you might expect, "nm" in openmdao refers to nano meter (10^-9 m).

These kinds of mistakes can and will happen and I think it would be best to have full blown names for those who want to use them. Using them should provide absolute clarity when using units.

Currently some of the units use "abbreviated form", e.g.

- "ha" for "hectare"
- "d" for "day"

While other don't:
- "year" instead of "a"
- "inch" instead of "in"

This is also confusing for the user. As mentioned before, I think abbreviated forms are much more dangerous to use and unit errors are bound to happen. Giving the users the option to use "full blown names" would be great!