I want to use the complex units for electric power:
S:VA volt-amperes (apparent power)
Q:VAR volt-ampere-reactive (reactive power)
P:W real power (supported yet)
Z: Ohm Impedance
phi= angle of Z and S

S=P+Q·j (using j instead i for imaginary unit to not confues with i for intensity)
S=V·I*
Z=V/I
Z=R+X·j

Don't know about the electrical units but it is customary for i to refer to the imaginary part of a complex number or sqrt(-1). In my opinion that one should not be changed. Personnally if a variable has the same symbol as a SMath unit I intentionally change the variable name to something else to avoid conflict with internal names. This is even though you can have a variable name with the same name as a unit without conflict. For example SMath will not confuse the variable name ft with the units 'ft (feet).

I'm going to try defining the variable j with the value i.
For the rest of units is mor complex

scooter,

Perhaps some of the units you propose would be good canidates for built-in units, you can create your own units. You can also create a substitue for imaginary i.



As I see it there are three different name formats. One is just the name by itself, the second is preceeded by a single quote and this is supposed to be used for units, the third is subscripted by typing dot. The third convention with out a subscript could be confusing though since you don't see the dot.