Units in the rkfixed function

[ValeryOchkov]

We can use units in Mathcad Prime by the solving ODE. It is very good! But I see one error:

[ValeryOchkov]

All is OK by the using the odesolve function:

[ViktorKorobov]

It is very strange:

rkfixed - 1 error

Rkadapt - 2 errors

Radau - no error

Viktor

[ValeryOchkov]

(1+2+0) / 3 = 1 Error!

And then I was happy that the unit can now be used by the solving differential equations

One calms me - in Maple we have same disorder by using units in the solving differential equations

[ValeryOchkov]

It seems that the units check does not work:

[ViktorKorobov]

..And more example (Mathcad Prime 3.0)

Viktor

[ValeryOchkov]

Mathcad sheet in attach

[HarveyHensley]

Valery,

The other solvers will probably work with units in a semi-fashion if you make the initial values dimensionless by dividing by their default units. The results will appear dimensionless also, so the units need to be reattached to the output. I got the first two solvers to work but didn't go on to the others.

So the state is half there regarding units. The derivative functions (your "f") can now have dimensions and they can be different, but not the initial values and results. The initial values can have dimensions provided they are all the same.

These results are similar to the sbval situation discussed earlier.

Harvey

[ValeryOchkov]

HARVEY HENSLEY wrote:

Valery,

The other solvers will probably work with units in a semi-fashion

Harvey

Thanks Harvey.

I know it very well. The life in Russia is in semi-fashion too. Not only now