The operators are defined in the standard Python module 'operator'.
sage: import operator
sage: (x+y)._operator is operator.add
True
sage: (x*y)._operator is operator.add
False
sage: (x*y)._operator is operator.mul
True
sage: (x**y)._operator is operator.mul
False
sage: (x**y)._operator is operator.pow
True
--Mike
On 10/1/07, Ondrej Certik <[EMAIL PROTECTED]> wrote:
>
> On 10/1/07, Mike Hansen <[EMAIL PROTECTED]> wrote:
> >
> > Hey Ondrej,
> >
> > While the correspondence is not exact, this should be enough to work:
> >
> > sage: e = x*y
> > sage: type(e)
> > <class 'sage.calculus.calculus.SymbolicArithmetic'>
> > sage: e._operands
> > [x, y]
> > sage: e._operator
> > <built-in function mul>
> > sage: e = exp(y)
> > sage: e._operands
> > [exp, y]
> > sage: type(e)
> > <class 'sage.calculus.calculus.SymbolicComposition'>
> > sage: var('z')
> > z
> > sage: f = x+y*z
> > sage: f._operands
> > [x, y*z]
> > sage: (y*z)._operands
> > [y, z]
> > sage: sin(y*z)._operands
> > [sin, y*z]
>
>
> Thanks a lot. BTW, how can I test the e._operator to be add? The only
> way I discovered is this:
>
> sage: str((x+y)._operator).find("add") != -1
> True
> sage: str((x*y)._operator).find("add") != -1
> False
> sage: str((x*y)._operator).find("mul") != -1
> True
> sage: str((x**y)._operator).find("mul") != -1
> False
> sage: str((x**y)._operator).find("pow") != -1
> True
>
> Which is quite fragile. :) Generally I think I know everything I need.
>
> Thanks,
> Ondrej
>
> >
>
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