[PyFeyn] Installation error

[Georg von Hippel]

Hi George,

thanks for looking into this. This is a problem that I found out about 
earlier (in fact when I posted the message you linked to) and decided not 
to fix, because PyX does not promise to keep a stable interface on things 
like _arrowhead() -- if one were to change this to the newer PyX version, 
it could break again with another update of PyX. On top of that, we'd have 
to surround every call to _arrowhead() with an if: statement chosing the 
right interface for the installed PyX version so as not the break PyFeyn 
on older PyXes. So I decided it wasn't worth fixing for the time being, as 
there is a perfectly reasonable workaround (downgrade to PyX 0.11.1). If 
and when somebody needs features present only in newer PyX versions, I 
will reconsider ...

Thanks again and best wishes,

    Georg


On Thu, 23 Jan 2014, George S. Williams wrote:

> On 1/21/2014 3:59 PM, Andy Buckley wrote:
>> Thanks for the help! If any of you happen to know what changes are
>> needed for compatibility with later PyX versions, it would be great to
>> do some automatic adaptation in the import to allow PyFeyn to work with
>> multiple PyX versions.
>> 
>> 
> Hey, Andy,
>
> I poked around a bit before I changed to an older PyX, and (if I'm 
> remembering correctly) saw several calls to pyx.deco._arrowhead() complaining 
> about not being passes enough arguments.
>
> After I changed PyX versions and found PyFeyn working and nothing else 
> broken, I quit looking...
>
> Hope this might be helpful- maybe it's the only thing that needs changing?
>
> Later,
> George