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All functions on this page are accessed via the np.random namespace and use the global MT19937 generator. Seed with np.random.seed() for reproducible results.

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random

Generate random floats in the half-open interval [0.0, 1.0). 
function random(size?: number | number[]): NDArray | number
NameTypeDefaultDescription
sizenumber | number[]undefinedOutput shape. If omitted, returns a single float.
Returns: NDArray | number — Random values in [0, 1). 
import * as np from 'numpy-ts';

np.random.seed(42);

// Single value
const x = np.random.random();

// 1-D array
const a = np.random.random(5);
// array([...])  shape [5]

// 2-D array
const b = np.random.random([3, 4]);
// array([...])  shape [3, 4]

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rand

Random values in a given shape. Variadic form of random — pass dimensions as separate arguments. 
function rand(...shape: number[]): NDArray | number
NameTypeDefaultDescription
...shapenumber[]—Dimensions of the returned array. If no arguments, returns a single float.
Returns: NDArray | number — Random values in [0, 1). 
import * as np from 'numpy-ts';

const a = np.random.rand(2, 3);
// array([...])  shape [2, 3]

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randn

Return samples from the standard normal distribution (mean=0, std=1). Variadic shape, like rand. 
function randn(...shape: number[]): NDArray | number
NameTypeDefaultDescription
...shapenumber[]—Dimensions of the returned array. If no arguments, returns a single float.
Returns: NDArray | number — Samples from the standard normal distribution. 
import * as np from 'numpy-ts';

const a = np.random.randn(1000);
// 1000 standard-normal samples

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randint

Return random integers from low (inclusive) to high (exclusive). 
function randint(
  low: number,
  high?: number | null,
  size?: number | number[],
  dtype?: DType
): NDArray | number
NameTypeDefaultDescription
lownumber—Lowest integer (inclusive). If high is omitted, this is treated as the upper bound and low defaults to 0.
highnumber | nullnullOne above the highest integer (exclusive).
sizenumber | number[]undefinedOutput shape. If omitted, returns a single integer.
dtypeDType'int64'Desired output dtype.
Returns: NDArray | number — Random integers in [low, high). 
import * as np from 'numpy-ts';

// 0 to 9
const a = np.random.randint(10);

// 5 to 14, shape [2, 3]
const b = np.random.randint(5, 15, [2, 3]);

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random_sample

Alias for random(). Return random floats in [0.0, 1.0). 
function random_sample(size?: number | number[]): NDArray | number
NameTypeDefaultDescription
sizenumber | number[]undefinedOutput shape.
Returns: NDArray | number — Random values in [0, 1).

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ranf

Alias for random(). Return random floats in [0.0, 1.0). 
function ranf(size?: number | number[]): NDArray | number
NameTypeDefaultDescription
sizenumber | number[]undefinedOutput shape.
Returns: NDArray | number — Random values in [0, 1).

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sample

Alias for random(). Return random floats in [0.0, 1.0). 
function sample(size?: number | number[]): NDArray | number
NameTypeDefaultDescription
sizenumber | number[]undefinedOutput shape.
Returns: NDArray | number — Random values in [0, 1).

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random_integers

Deprecated. Use randint instead.
Return random integers between low and high, inclusive on both ends. 
function random_integers(
  low: number,
  high?: number,
  size?: number | number[]
): NDArray | number
NameTypeDefaultDescription
lownumber—Lowest integer. If high is omitted, range is [1, low].
highnumberundefinedHighest integer (inclusive).
sizenumber | number[]undefinedOutput shape.
Returns: NDArray | number — Random integers in [low, high]. 
import * as np from 'numpy-ts';

// Random integers from 1 to 6 (inclusive), like a die roll
const die = np.random.random_integers(1, 6, [10]);

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bytes

Return random bytes as a Uint8Array. 
function bytes(length: number): Uint8Array
NameTypeDefaultDescription
lengthnumber—Number of random bytes to generate.
Returns: Uint8Array — Array of random bytes. 
import * as np from 'numpy-ts';

const b = np.random.bytes(16);
// Uint8Array of 16 random bytes

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choice

Generate a random sample from a given 1-D array or from range(a) when a is an integer. 
function choice(
  a: number | ArrayLike,
  size?: number | number[],
  replace?: boolean,
  p?: ArrayLike
): NDArray | number
NameTypeDefaultDescription
anumber | ArrayLike—If number, sample from 0..a-1; otherwise sample from the provided values.
sizenumber | number[]undefinedOutput shape.
replacebooleantrueWhether sampling is with replacement.
pArrayLikeundefinedOptional probabilities for each entry in a.

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permutation

Randomly permute a sequence or return a permuted range. 
function permutation(x: number | ArrayLike): NDArray
NameTypeDefaultDescription
xnumber | ArrayLike—If number, permute 0..x-1; otherwise permute the input values.

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shuffle

Shuffle an array in place along the first axis. 
function shuffle(x: ArrayLike): void
NameTypeDefaultDescription
xArrayLike—Array to shuffle in place.