Function malachite_base::num::random::striped::striped_random_unsigned_vecs

source · [−]

pub fn striped_random_unsigned_vecs<T: PrimitiveUnsigned>(
    seed: Seed, 
    mean_stripe_numerator: u64, 
    mean_stripe_denominator: u64, 
    mean_length_numerator: u64, 
    mean_length_denominator: u64
) -> StripedRandomUnsignedVecs<T, GeometricRandomNaturalValues<u64>>ⓘNotable traits for StripedRandomUnsignedVecs<T, I>impl<T: PrimitiveUnsigned, I: Iterator<Item = u64>> Iterator for StripedRandomUnsignedVecs<T, I>    type Item = Vec<T>;

Expand description

Generates random striped Vecs of unsigneds.

See here for more information.

The lengths of the Vecs are sampled from a geometric distribution with a specified mean $m$, equal to mean_length_numerator / mean_length_denominator. $m$ must be greater than 0.

The mean run length (before the bit sequences are truncated) is $m$ = mean_stripe_numerator / mean_stripe_denominator.

$$ P((x_0, x_1, \ldots, x_{n-1})) = \frac{m^n}{(m+1)^{n+1}}\prod_{i=0}^{n-1}P(x_i). $$

Expected complexity per iteration

$T(n) = O(n)$

$M(n) = O(n)$

where $T$ is time, $M$ is additional memory, and $n$ is mean_length_numerator / mean_length_denominator.

Panics

Panics if mean_stripe_denominator is zero, if mean_stripe_numerator <= mean_stripe_denominator, if mean_length_numerator or mean_length_denominator are zero, or, if after being reduced to lowest terms, their sum is greater than or equal to $2^{64}$.

Examples

use malachite_base::iterators::prefix_to_string;
use malachite_base::num::random::striped::striped_random_unsigned_vecs;
use malachite_base::random::EXAMPLE_SEED;
use malachite_base::strings::{ToBinaryString, ToDebugString};

assert_eq!(
    prefix_to_string(
        striped_random_unsigned_vecs::<u8>(EXAMPLE_SEED, 10, 1, 2, 1)
                .map(
                    |xs| prefix_to_string(
                        xs.into_iter().map(|x: u8| x.to_binary_string()),
                        100
                    )
                ),
        10,
    ),
    "[[0, 0, 111000, 0, 11111110, 10000001], [0], \
    [11110000, 11111111, 11111111, 11111111, 11, 0, 10000000, 11111], [0], \
    [10000, 0, 11111100, 11111111, 1111111, 11111000, 11, 0, 0, 10011000, 11111111, 111, 0, \
    0], [], [11111111, 11111111, 11111111, 11111111, 10111111], [0, 0, 0, 11110000], \
    [11111111], [], ...]"
);