Hi Roustam,
No, not that I know of. In order to get something like this into FriCAS,
it needs three things
1) Someone who is interested and continues to ask for such a feature,
2) a discussion here at fricas-devel to find a good design,
3) someone, who is able and willing to implement it.
Would you like to take part in all of the three items?
I somehow think that an implementation should be rather simple, at least
the basic functionality. We can take a set of variables (see
https://en.wikipedia.org/wiki/International_System_of_Units)
s, m, kg, A, K, mol, cd
and implement a unit system as Laurent polynomials over these variables
or rather as the multiplicative group of these variables together with a
prefactor from a certain ring (e.g. Float) and extend this group by a
(restricted) addition where x+y can only be done if x and y agree in the
powerproduct part of their variables.
Clearly, if one wants other systems of units like CGS, then one
implements the same domain as above just with other variable names.
The real work then is to add conversion factors if one transforms an
element of one unit system to another unit system.
Sounds like an easy exercise to learn programming in FriCAS.
Or do you want something else? What?
Ralf