Jump to content

Discrete helpers/binv

From Wikiversity

This is a simple helper class for binary vectors.

from discretehelpers.binv import Binv


binv = Binv('1101000')

# properties
assert binv.length == 7
assert binv.weight == 3
assert binv.vector == [True, True, False, True, False, False, False]
assert binv.string == '1101000'
assert binv.exposet == {0, 1, 3}  # little-endian
assert binv.intval == 11  # 2**0 + 2**1 + 2**3
assert binv.changes == 3  # changes between 0 and 1 (down, up, down)
assert binv.complement == ~binv == Binv('0010111')

# equivalent instantiations
assert binv == Binv('11 01 000')
assert binv == Binv([1, 1, 0, 1, 0, 0, 0])
assert binv == Binv(intval=11, length=7)
assert binv == Binv(exposet={0, 1, 3}, length=7)

The property pretty can be used when the length is a power of two up to 64:

Binv(intval=38505).pretty == '1001 0110 0110 1001'


integer values

[edit | edit source]
The smallest bit is on the left!
The smallest bit is on the left!

An important use is conversion to and from decimal. The interpretation is little-endian, i.e. the least-significant bit is on the left.

for i in range(16):
    s = Binv(intval=i, length=4).string
    padded_i = str(i).zfill(2)
    print(padded_i, s)
00 0000
01 1000
02 0100
03 1100
04 0010
05 1010
06 0110
07 1110
08 0001
09 1001
10 0101
11 1101
12 0011
13 1011
14 0111
15 1111