Base Conversion

[Eviatar]

I coded a simple function to convert any base to another, and I want
to submit it as a patch. Where in the source code could this fit?

Thanks in advance.

[David Roe]

This can currently be done by

sage: a = ZZ("sage",base=32); a
928270
sage: a.str(base=32)
'sage'
sage: a.str(base=36)
'jw9a'

For bases outside of 2..36, you can work with lists:

sage: b = ZZ([4,1,7],base=100)
sage: b
70104
sage: b.digits(base=71)
[27, 64, 13]
sage: 27 + 64*71 + 13*71^2
70104

For a function that makes this functionality easier to access, I would suggest sage/rings/arith.py.  If you want to modify this behavior in some ways, then you should take a look at sage/rings/integer.pyx.
David

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[Eviatar]

Thank you,

I wasn't aware of that functionality. However, I think my function is
more convenient since you can directly convert bases, instead of using
base 10 as an intermediary step.

[Nick Alexander]

sage: ZZ(15).digits(2)
[1, 1, 1, 1]
sage: ZZ(15).digits(3)
[0, 2, 1]

Nick

[Eviatar]

Yes, but can you go directly from base 2 to base 4, for example? I
guess this would work, ZZ(23,base=2).str(base=4), but it's not very
convenient.

[Nick Alexander]

sage: ZZ([1, 2], base=3)
7
sage: ZZ([1, 2], base=3).digits(2)
[1, 1, 1]

My opinion is that this is short and already well supported, and much
more general than the special function OP suggests.

Nick