Hi,

I have run into a problem with using units which are reciprocals - specifically Ohms and Siemens.

If I try to add a quantity with units Ohms to the reciprocal of a quantity with units Siemens, an error occurs: Units don't match.

Due to computer limitations where I am presently, I have only text entry.

Example:

Ra := 1 Ohm
Ga := 1 S
Rsum := Ra + 1/Ga = "units don't match"

But they do cancel:

Rprod := Ra * Ga = 1

Is there a work-around I'm missing somehow?

Thanks,
Fred

Hello Fred,

it is a bug; as workaround you can transit through a 3rd variable with symbolic optimization on his definition, then it is possible to evaluate numerically this variable in a separate region (see the cloud example)

Hi,

I was trying to implement a formula to calculate needed inductance on a flyback transformer and the program reports that units do not match. However splitting the formula in smaller pieces I was able to get the result out of it.
units dont match.sm (34 KiB) downloaded 60 time(s).

Thank you.

It is the same bug as the one shown in the first post, so I moved your post here.

The problem is related to the numeric evaluation, but there is a workaround:
- remove the RHS (the evaluation = and all after it)
- change optimization to symbolical
- show the result alone (Lp=#)


Bug reported as SS-2368

Wrote

It is the same bug as the one shown in the first post, so I moved your post here.

The problem is related to the numeric evaluation, but there is a workaround:
- remove the RHS (the evaluation = and all after it)
- change optimization to symbolical
- show the result alone (Lp=#)


Bug reported as SS-2368

Thank you Davide, seems to work following your advice.
Emil

Both issues fixed. See latest available nightly build: http://en.smath.info/forum/yaf_postst7698_SMath-Studio-0-98-6073--19-August-2016.aspx