sidef-scripts/Other/hex_randomness_info.sf

#!/usr/bin/ruby

# Show some information about the randomness of a given hex-encoded string.

# See also:
#   https://rosettacode.org/wiki/Entropy

func entropy(bytes) {
  var counts = bytes.freq
  var len = bytes.len
  [0, counts.values.map {|count|
    var freq = count/len; freq * freq.log2 }...
  ]«-»
}

func arithmetic_mean(bytes) {
    Math.arithmetic_mean(bytes.map {_+1}...)
}

func geometric_mean(bytes) {
    Math.geometric_mean(bytes.map {_+1}...)
}

func harmonic_mean(bytes) {
    Math.harmonic_mean(bytes.map {_+1}...)
}

var hex = ARGV[0] \\ die "usage: #{__MAIN__} [hex string]\n"

if (hex !~ /^[[:xdigit:]]+\z/) {
    die "The input must be a hexadecimal string!\n"
}

var ascii = hex.hex2ascii
var bytes = ascii.bytes
var bits  = ascii.ascii2hex.hex.bits

var rand_bytes = bytes.len.random_bytes
var rand_bits  = bits.len.of { [0,1].rand }

printf(<<-"EOT",
        BYTE TESTS      |       VALUE
    ---------------------------------------------
    Entropy(bytes)      : %8.4g (rand: %6.4g)
    A(bytes)            : %8.4g (rand: %6.4g)
    G(bytes)            : %8.4g (rand: %6.4g)
    H(bytes)            : %8.4g (rand: %6.4g)

        BIT TESTS       |       VALUE
    ---------------------------------------------
    Entropy(bits)       : %8.4g (rand: %6.4g)
    A(bits)             : %8.4g (rand: %6.4g)
    G(bits)             : %8.4g (rand: %6.4g)
    H(bits)             : %8.4g (rand: %6.4g)
    EOT

    entropy(bytes), entropy(rand_bytes),
    arithmetic_mean(bytes), arithmetic_mean(rand_bytes),
    geometric_mean(bytes), geometric_mean(rand_bytes),
    harmonic_mean(bytes), harmonic_mean(rand_bytes),

    entropy(bits), entropy(rand_bits),
    arithmetic_mean(bits), arithmetic_mean(rand_bits),
    geometric_mean(bits), geometric_mean(rand_bits),
    harmonic_mean(bits), harmonic_mean(rand_bits)
)

__END__

# Example:
$ sidef hex_randomness_info.sf $(sidef -E 'File("/usr/bin/perl").read(:raw).ascii2hex.say')

    BYTE TESTS      |       VALUE
---------------------------------------------
Entropy(bytes)      :    1.947 (rand:  7.987)
A(bytes)            :    17.18 (rand:  129.2)
G(bytes)            :    2.083 (rand:   96.3)
H(bytes)            :    1.212 (rand:  42.71)

    BIT TESTS       |       VALUE
---------------------------------------------
Entropy(bits)       :   0.4062 (rand:      1)
A(bits)             :    1.081 (rand:  1.501)
G(bits)             :    1.058 (rand:  1.415)
H(bits)             :    1.042 (rand:  1.334)