[sage-support] Re: Setting symbol for imaginary unit?

[Tim Lahey]

On Dec 4, 2008, at 5:13 PM, Jason Grout wrote:

Tim Lahey wrote:

The only problem I see with this is that it doesn't free up the
original. One
reason for changing the symbolic I, is to be able to use it for other
variables.

Sure it does:

sage: _j = I
sage: _j.rename("_j")
sage: var("I")
I
sage: type(I)
<class 'sage.calculus.calculus.SymbolicVariable'>
sage: I^2
I^2
sage: type(_j)
<class 'sage.functions.constants.I_class'>
sage: _j^2
-1


In fact, you could go one further.  "I" is just defined by:

I = sage.functions.I_class()

(in sage/functions/constants.py).  So you could just do:

sage: _j = sage.functions.constants.I_class()


you want, whenever you want.

and not even touch the global I variable. Then assign I to be whatever

Oh, thanks. This is definitely a good thing.

Cheers,

Tim.

---
Tim Lahey
PhD Candidate, Systems Design Engineering
University of Waterloo
http://www.linkedin.com/in/timlahey

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