[GiNaC-list] Weird: symbol * ddq_i, my_ex.subs((*ddq_i)==0) my_ex.subs(*ddq_i==0)my_ex.subs(symbol(*ddq_i)==0) ??

Javier Ros jros at unavarra.es
Wed Jul 27 23:09:21 CEST 2011


On Wed, Jul 27, 2011 at 8:41 PM, Jens Vollinga
<jens.vollinga at googlemail.com> wrote:
> Hi Javier,
> your information is a bit confusing. First you write:
I'm sorry.

> On 27.07.2011 19:23, Javier Ros wrote:
>> the following trivial simplifications
>> my_ex.subs((*ddq_i)==0)
> ...
>> go wrong no correct substitution, in different ways
> then you write:
>> Interestingly  until now I was simplifying correctly using
>> my_ex.subs((*ddq_i)==0)

You can disregard this sentence.

> So, once it goes wrong, then it goes well?!? Did you upgrade GiNaC to a
> newer version, maybe?

Disregard the my_ex.subs((*ddq_i)==0) goes OK thing,

> Anyway, could you, if possible, send a complete code example to explain your
> problem? It is hard to guess what the problem might be, otherwise.

It's going to take some time to isolate, as I'm using a library that
I've build on top of GiNaC to generate the offending my, but I'll try
if I can reproduce it using plain GiNaC, writing and reading it back
in a plain
GiNaC program.

In any case I suppose that the trivial simplifications




should coincident with these



But unfortunately only the last two are working.

Do you agree that this is not normal behavior?.

Thank you,


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