How can I have Celcius not Kelvin on the X-axes of Prime plot

[ValeryOchkov]

Help please - see the attach

[Werner_E · Accepted solution]

Oviously it does not work the way it should (by simply chosing °C in the unit box) so one crude way is to do the conversion manually. Not very satisfying, I guess.

[ValeryOchkov]

Thanks, Werner!

Same bag:

[Fred_Kohlhepp]

The Kelvin and Rankine scales are absolute--they both start at absolute zero and are therefore a ratio.  Centigrade (Celsius) and Fahrenheit scales have arbitrary (and different) zero reference points.  Mathcad has to use functions for that conversion.  If you look under units the the ribbon, you can select which units to plot with.

[ValeryOchkov]

Not all is fine in Mathcad 15 too

[Werner_E]

Hi Fred!

Think we found a bug in Prime 5!

What you show was exactly what I tried first (and Valery sure did so, too) and it failed because we both used Prime 5.

It works OK in Prime 4 but throws an error in Prime 5!

So the bug was freshly introduced with Prime 5 (and we thought there would be no development of Prime any more 😉

[ttokoro]

[ValeryOchkov]

Maple has:

1. Fahrenheit
2. Celsius
3. centigrade
4. Reaumur
5. Rankine
6. Kelvin

But the 7 not the 6 is a fine number! Do you know 7-th temperature scale? I Know!

[LucMeekes]

First please explain the difference between 'Celsius' and 'centigrade' .

Luc

[Fred_Kohlhepp]

I agree:  

From WIKIPEDIA:

Before being renamed to honor Anders Celsius in 1948, the unit was called centigrade, from the Latin centum, which means 100, and gradus, which means steps.

[ValeryOchkov]

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@Fred_Kohlhepp wrote:

I agree:  

From WIKIPEDIA:

Before being renamed to honor Anders Celsius in 1948, the unit was called centigrade, from the Latin centum, which means 100, and gradus, which means steps.

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sorry - not so simple

[LucMeekes]

So, with that settled (Thanks! Fred),

the 6th through 8th temperature scales, or units, could be Delisle, Newton and Romer;

per https://en.wikipedia.org/wiki/Conversion_of_units_of_temperature#Comparison_of_temperature_scales

Of these, Delisle is interesting because it goes hotter for lower values...

Luc

[ValeryOchkov]

One interesting Mathcad Web-sheet:

The International Temperature Scale of 1990 (ITS-90)

[Werner_E]

@ttokoro 

Valery needs/wants  °C on the abscissa!

[ttokoro]

I understand what is the problem. X-axes allows K or R and not degree C or degree F. (x=x*unit ,not x=x*unit+C*unit)

So x axes can use the unit of delta degree C.

[Fred_Kohlhepp]

But Prime 4 (Expresseven) allows deg C on the x axis as well

[Fred_Kohlhepp]

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@Werner_E wrote:

So the bug was freshly introduced with Prime 5 (and we thought there would be no development of Prime any more 😉

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And the beat goes on . . . .

I guess with the new fancy graphing utility the built-in graphs could be farmed out to the interns.

[Werner_E]

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@Fred_Kohlhepp wrote:

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@Werner_E wrote:

So the bug was freshly introduced with Prime 5 (and we thought there would be no development of Prime any more 😉

---

And the beat goes on . . . .

I guess with the new fancy graphing utility the built-in graphs could be farmed out to the interns.

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At least this new plot add-in can't show the bug in question here as it is totally unit-unaware. Hurray!