how to handle odd units

[karlp]

I know that I can provide my own entire array of units, but do you have ideas on how best to handle things like "Vrms" and Vpp, while still keeping all the existing SI unit prefixes? so I can have mVrms and uVrms without having to to duplicate all the units for all the combinations?

I'm probably just going to ignore supporting this in the direct SOURce#:APPLy:SIN [freq], [ampl], [offset] type functions, and only allow changing it via the explicit SOURce#:VOLTage:UNIT command, but was wondering if you had any ideas on how best to handle this

[j123b567]

Because of collisions in units and their prefixes, you must specify all combinations you want. Units prefixes are case insensitive.

Consider these examples:

• What is MHZ? - mega Hertz or milli Hertz
• What is MV? - mega Volt or milli Volt
• What is MOHM? - mega Ohm or milli Ohm

It all depends on your application and it is not possible to generate prefixes automaticly.

[karlp]

I more meant suffixes. I understand the M problem above, and SCPI even just says it's banned to use milli hertz, milli ohms and megavolts.

I was more meaning things like 400uVrms, 400mVrms and 400Vrms and 400uVpp, 400mVpp, 400Vpp, without specifying Vrms and Vpp as separate units, so the prefix would still do the x1000, /1000 type multipliers, but the suffix could have some other factor after the prefix was applied. Just idle thoughts really.

[j123b567]

I now understand what you want. There could be one array of units and each unit connected to array with possible prefixes for that unit.

V -> U,M,,K
Vrms -> U,M,,K
OHM -> ,K,M
HZ -> ,K,M,G

But now, it is not possible and it is hard to implement. The best way now is to expand all possible prefixes with all possible suffixes.

[karlp]

Indeed, I know it's not really possible in the current library, just something to think about .)

[j123b567]

Feel free to implement it ;)

[j123b567]

Just make two separate issues from this #26 and #25 so closing this.