units anomily

[cyrille de brébisson]

Hello


> I would have expected something as simple as units conversion to be easier than that on the Prime.

Unit conversion are anything BUT simple (unfortunately).

The problem of °C and °F set aside, the 'sto' shortcut as in 1_m▶_cm is quite simple and pretty much to the point with very few keystrokes (considering the possibility range of Prime).



Now, working with °C and °F, this is a whole other can of worms.
°C and °F are not technically units. This is because they are not 0 based. ie, 0°C does not denote the absolute 0 with negative units denoting anti-heat.
This is where the problem lies.
This means that 1°C is not (always) equal to 1°C.
If I say: the temperature is 1°C, I mean by that that the temperature is 247K
When I say the temperature change is 1°C, I mean that the temperature change is 1K
But, the calculator does not get the context. When you tell it to convert 1°C to °F or K, it does not know if the 1°C is the result of a previous subtraction or an 'absolute' temperature.

Bernard, in the the CAS has decided that no serious (real life) math/physics calculations will/should use °C and °F, and is basically banning them. It is a defendable position, which makes sense, and which also makes the software developer life much much easier.

In home, we recognized that some users would want to do some computation on °C and °F, so we did some extra work to allow, with restrictions, in order to reduce the occurrences of "vitum pillum" (pig latin for "javelot in foot", (sorry I forgot the declination), or, as we would say in modern english: shooting oneself in the foot).
But it still fall short of expectations, due to the problem mentioned above, the calculator can not know, when you use 1°C if this is 0 based, or 246°K based.

Cyrille