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Subject: Re: What should Matrix([1,2,3]) give?
From: Vinzent Steinberg <vinzent.steinb...@googlemail.com>
To: sympy <sympy@googlegroups.com>
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On Aug 29, 8:33=A0pm, Aaron Meurer <asmeu...@gmail.com> wrote:
> I see. =A0So the main reason for the numpy syntax is consistency with
> broadcasting, which doesn't really make sense in SymPy (or at least
> not at the moment). =A0Actually, I originally thought we should try to
> match the numpy syntaxes, but as I look at them, I'm not sure. =A0For
> example, I said we should try to match the slicing syntax, but there
> are some aspects of the way numpy does that that some people don't
> like (see issuehttp://code.google.com/p/sympy/issues/detail?id=3D2544).
>
> So I think we need to consider things from the SymPy point of view,
> like you said. =A0One thing to consider is that eventually we will have
> an ImmutableMatrix(), which is Basic, but which will have the same
> syntax as Matrix(). =A0So it will need to satisfy the
> ImmutableMatrix(*args) invariant.
>
> We also should consider backwards compatibility breaks of our own.
> Changing Matrix([1, 2, 3]) to a row vector will break a lot of code.

I think we can break numpy compatibility here. (IIRC they are not that
happy with their matrix interface anyway.)

For me Matrix([1,2,3]) returning a column vector is just convenient,
because it is closer to the mathematical conventions and most often
used. If you want a row vector, you can use the explicit
Matrix([[1,2,3]]) (or transposition of course).