[10.6] Add Units To Built-In Units Menu - Texas Instruments TI-89 Tip List

tmpcnv(TF*_°F,_°C)
which gives the result
0.5556·(TF-32)·_°C

[10.6] Add units to built-in Units menu

The built-in 89/92+ Units menu is lacking many common units. For example, the Area menu has only
two units, and the Accelration menu has no units. You can remedy this by defining your own units, in
terms of the built-in units. In addition, the 89/92+ can recognize the categories for many of these units,
and place them in the correct category so you can access them with the [UNITS] key.
The basic idea is to store the unit definition as a user-defined unit. For example, to save a cubic inches
unit as a unit called _in3, use
_in^3→_in3
Note the use of the underscore character '_', which defines a unit. Now the Volume units menu shows
...
_galUK
_in3
_l
...
This unit can be used just like any other built-in unit. For example, to convert 5 liters to cubic inches,
use
5_l▶_in3
If you use many user-defined units, it is convenient to have a program that defines them all at once.
Here is an example of such a program:
units()
Prgm
©Define new units
©10oct00 dburkett@infinet.com
©Area units
_in^2→_in2
_ft^2→_ft2
_yd^2→_yd2
_mi^2→_mi2
_cm^2→_cm2
_m^2→_m2
_km^2→_km2
©Volume units
_in^3→_in3
_ft^3→_ft3
_yd^3→_yd3
_mi^3→_mi3
_cm^3→_cm3
_m^3→_m3
_km^3→_km3
which returns 305.12_in3
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