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sage code for decimal to binary expansion

asked 2016-12-16 15:36:54 +0200

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k=4 then (0100)

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answered 2016-12-16 15:57:34 +0200

kcrisman gravatar image

Interestingly, this hasn't been properly asked sometimes. Here is an example:

sage: a = 15
sage: a.binary()
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answered 2016-12-16 16:50:34 +0200

This gives the list of digits rather than a string:

sage: a = 14
sage: a.digits(2)
[0, 1, 1, 1]

Note that these are listed starting with the units digit.

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So in either case you have to do something... maybe b = a.digits(2); b.reverse() like this?

kcrisman gravatar imagekcrisman ( 2016-12-17 15:14:59 +0200 )edit

b = a.digits(2); b.reverse(); ''.join(map(str,b)) pretty much does the same thing as a.binary(). Doing this with other primitive data types can be done using the Python 'struct' package. For example, for floats: ''.join(bin(ord(c)).replace('0b', '').rjust(8, '0') for c in struct.pack('!f', num)). Anyone has any idea how to print the binary representation for Sage ring data types such as Rationals?

VivekGandhi gravatar imageVivekGandhi ( 2019-09-27 11:22:52 +0200 )edit

@VivekGandhi: what is the binary representation for a rational number? Is a.numerator().binary() + '/' + a.denominator().binary() what you mean? By the way, I don't think there can be a general answer for all "Sage ring data types," since they won't all have a meaningful binary representation.

John Palmieri gravatar imageJohn Palmieri ( 2019-09-27 23:06:47 +0200 )edit

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Asked: 2016-12-16 15:36:54 +0200

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Last updated: Dec 16 '16