Mike, I'm the author of the referenced pull request ( https://github.com/sympy/sympy/pull/19479) for the equation type. There is a version you can try without having to set up SymPy for development (see https://github.com/gutow/Algebra_with_Sympy, which I try to keep roughly equivalent to the developing SymPy update). As you have interest in this, I would appreciate you trying it and providing feedback about behavior in the pull request. I am hoping to work on this some more as soon as I get things lined up for my Fall classes. I will be trying the Algebra_with_Sympy code with one of my classes this Fall.
Regards, Jonathan On Sunday, July 26, 2020 at 1:19:20 PM UTC-5 mikhae...@umontpellier.fr wrote: > Thanks a lot for your answer. I belived "Eq" was a reduction for > "Equation" and not for "Equality". > I started to do something similar to what you mention, but your way to do > it is smarter and I did and I will use your way. > Thanks a lot, > Mike. > > Question : As you answerd nicely my question I require to close this > request. How may I do it ? > > > Le dimanche 26 juillet 2020 20:13:11 UTC+2, Davide Sandona' a écrit : > >> Hello Mike, >> sadly, what you are trying to do is not easily possible! You are thinking >> of Eq as an equation, instead in Sympy it is an alias for the class >> Equality. They are conceptually different and the behaviour you are trying >> to represent is not possible: you can not apply the same mathematical >> operation to both sides simultaneously. If you happen to have objects of >> type Equality, it is better to convert them to an expression and perform a >> manipulation, for example: >> >> eq.rewrite(sp.Add).collect(a) / a >> >> Alternatively: >> >> sp.Eq(*[arg / a for arg in eq.args]) >> >> If you absolutely need an object to represent an equation, take a look at >> the source code of this pull-request [1]. It's not perfect, but it is a >> starting point; with that class Equation, you can apply the same >> mathematical operation to both sides simultaneously. >> >> [1] https://github.com/sympy/sympy/pull/19479 >> >> Davide. >> >> >> Il giorno dom 26 lug 2020 alle ore 19:39 Mikhael Myara < >> mikhae...@umontpellier.fr> ha scritto: >> > a simple code : >>> >>> import sympy as sp >>> sp.var('a b c',nonzero=True) >>> eq = Eq(a*b,a*c) >>> display(eq) >>> display(eq.simplify()) >>> >>> Both display exhibit : ab = ac >>> >>> I would have liked sympy to simply remove 'a', which is possible because >>> I mentioned 'a' is nonzero. >>> >>> What's wrong ? >>> >>> Best regards, Mike >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sympy" group. >>> >> To unsubscribe from this group and stop receiving emails from it, send an >>> email to sy...@googlegroups.com. >> >> >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sympy/23535fa8-2842-4259-96aa-4862292c8ae1o%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/sympy/23535fa8-2842-4259-96aa-4862292c8ae1o%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/4c2de2ab-c539-46ef-afc3-5bc3f544e91fn%40googlegroups.com.
