Function

Static Public Summary
public	abs(A: Array<mixed>): Array<mixed> Get a copy of an array with absolute values of the original array entries.
public	accuracy(yTrue: Array<mixed>, yPred: Array<mixed>, normalize: boolean): number Evaluate the accuracy of a set of predictions.
public	argFilter(array: Array<mixed>, callback: function(element: mixed, !index: Number): boolean): Array<number> Filter an array and return the array indices where the filter was matched.
public	argMax(array: Array<number>): number Get array key corresponding to largest element in the array.
public	argSort(array: Array<mixed>, compareFunction: function(a: mixed, b: mixed): Number): Array<number> Sort an array and return the array indices of the sorted elements.
public	auroc(yTrue: Array<number>, yPred: Array<mixed>): number Calculate the area under the receiver-operator characteristic curve (AUROC) for a set of predictions.
public	binaryIntervalSearch(array: Array<number>, value: number): number Perform a binary search in a sorted array A to find the index i such that the search value is larger than or equal to A[i], and strictly smaller than A[i+1].
public	concatenate(axis: number, S: ...Array<mixed>): Array Concatenate two or more n-dimensional arrays.
public	dot(x: Array<number>, y: Array<number>): number Calculate dot product of two vectors.
public	equal(array1: Array<mixed> \| mixed, array2: Array<mixed> \| mixed): boolean Deep check whether two arrays are equal: sub-arrays will be traversed, and strong type checking is enabled.
public	fill(A: Array<mixed>, value: mixed): Array<mixed> Set all entries in an array to a specific value and return the resulting array.
public	flatten(A: Array<mixed>): Array<mixed> Recursively flatten an array.
public	full(shape: Array<number>, value: mixed): Array<mixed> Initialize an n-dimensional array of a certain value.
public	getArrayElement(A: Array<mixed>, index: Array<number>): mixed Get an arbitrary element from an array, using another array to determine the index inside the first array.
public	getShape(A: Array<mixed>): Array<number> Find the shape of an array, i.e.
public	getTouchCoordinate(e: object, coordinate: string): * Get touch coordinate (x or y) from touchpad input.
public	internalSum(A: Array<number>): number Sum all elements of an array.
public	linspace(a: number, b: number, n: number): Array<number> Generate n points on the interval (a,b), with intervals (b-a)/(n-1).
public	loadDatasetFromCSV(input: string, callback: function(X: Array<Array<number>>, y: Array<number>)) Load a dataset (features and target) from some CSV input string.
public	loadDatasetFromRemoteCSV(url: string, callback: function(X: Array<Array<number>>, y: Array<number>)) Load a dataset from a remote CSV file.
public	loadIris(callback: function(X: Array<Array<number>>, y: Array<number>)) Load the iris dataset.
public	meshGrid(x: Array<number>, y: Array<number>): Array<Array<Array<number>>> Generate a mesh grid, i.e.
public	norm(x: Array<number>): * Calculate the Euclidian norm of a vector.
public	pad(A: Array<mixed>, paddingLengths: Array<number>\|Array<Array.<number>>, paddingValues: Array<number>\|Array<Array.<number>>, axes: Array<number>): Array<mixed> Pad an array along one or multiple axes.
public	permuteAxes(A: Array<mixed>, newAxes: Array<number>): Array<mixed> Permute the axes of an input array.
public	power(A: Array<mixed>, y: number \| Array<number>): Array<mixed> Raise all elements in an array to some power.
public	rand(a: number, b: number): number Generate a random number between a lower bound (inclusive) and an upper bound (exclusive).
public	randint(a: number, b: number, shape: number \| Array<number>): number \| Array<mixed> Generate a random integer between a lower bound (inclusive) and an upper bound (exclusive).
public	repeat(axis: number, numRepeats: number, A: Array<mixed>): Array<mixed> Repeat an array multiple times along an axis.
public	reshape(A: Array<mixed>, shape: Array<number>): Array<mixed> Reshape an array into a different shape.
public	sample(input: Array<mixed>, number: number, withReplacement: boolean, weights: Array<number> \| string): Array<mixed> Take a random sample with or without replacement from an array.
public	sampleFisherYates(input: Array<mixed>, number: number): Array<mixed> Take a random sample without replacement from an array.
public	scale(A: Array<mixed>, c: number): Array<mixed> Multiply each element of an array by a scalar (i.e.
public	setArrayElement(A: Array<mixed>, index: Array<number>, value: mixed): * Set an arbitrary element in an array, using another array to determine the index inside the array.
public	shuffle(S: ...Array<mixed>): Array<Array<mixed>> Randomly shuffle multiple arrays in the primary (first) axis.
public	slice(A: Array<mixed>, start: Array<number>, stop: Array<number>): Array<mixed> Take a slice out of an input array.
public	subBlock(A: Array<mixed>, offset: Array<number>, shape: Array<number>): Array<mixed> this function was deprecated. Use slice() instead Extract a sub-block of a matrix of a particular shape at a particular position.
public	sum(S: ...Array<mixed>): Array<mixed> Calculate element-wise sum of two or more arrays.
public	trainTestSplit(input: Array<Array<mixed>>, optionsUser: Object): Array Split a dataset into a training and a test set.
public	transpose(A: Array<Array<number>>): Array<Array<number>> Get the transpose of a matrix or vector.
public	unique(array: Array<mixed>): Array<mixed> Get unique elements in array
public	valueCounts(array: Array<mixed>): Array<Array<mixed>> Count the occurrences of the unique values in an array
public	valueVector(n: number, value: mixed): * Initialize a vector of a certain length with a specific value in each entry.
public	wrapSlice(array: Array<mixed>, begin: number, end: number): Array<mixed> Take a slice out of an array, but wrap around the beginning an end of the array.
public	zeros(shape: Array<number>): Array<mixed> Initialize an n-dimensional array of zeros.
public	zipWithIndex(array: Array<mixed>): Array<Array<mixed>> From an input array, create a new array where each element is comprised of a 2-dimensional array where the first element is the original array entry and the second element is its index

Static Public

public abs(A: Array<mixed>): Array<mixed> source

import {abs} from '@jsmlt/jsmlt/src/arrays/index.js'

Get a copy of an array with absolute values of the original array entries.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to get absolute values array from

Return:

Array<mixed>

Array with absolute values

public accuracy(yTrue: Array<mixed>, yPred: Array<mixed>, normalize: boolean): number source

import {accuracy} from '@jsmlt/jsmlt/src/validation/metrics/index.js'

Evaluate the accuracy of a set of predictions.

Params:

Name	Type	Attribute	Description
yTrue	Array<mixed>		True labels
yPred	Array<mixed>		Predicted labels
normalize	boolean	optional default: true	Whether to normalize the accuracy to a range between 0 and 1. In this context, 0 means no predictions were correct, and 1 means all predictions were correct. If set to false, the integer number of correct predictions is returned

Return:

number

Proportion of correct predictions (if normalize=true) or integer number of correct predictions (if normalize=false)

public argFilter(array: Array<mixed>, callback: function(element: mixed, !index: Number): boolean): Array<number> source

import {argFilter} from '@jsmlt/jsmlt/src/arrays/index.js'

Filter an array and return the array indices where the filter was matched. Corresponds to JavaScript's native Array.filter(), but instead of returning the elements that match the filter criteria, it returns the indices of the elements matching the filter.

Params:

Name	Type	Attribute	Description
array	Array<mixed>		Array to be filtered
callback	function(element: mixed, !index: Number): boolean		Callback function to be used for filtering. This function takes an array element and possibly its index as its input and should return true when the index should be used (filtered) and false when it shouldn't

Return:

Array<number>

Array of array indices in the original array where the array element matches the filter

public argMax(array: Array<number>): number source

import {argMax} from '@jsmlt/jsmlt/src/arrays/index.js'

Get array key corresponding to largest element in the array.

Params:

Name	Type	Attribute	Description
array	Array<number>		Input array

Return:

number

Index of array element with largest value

public argSort(array: Array<mixed>, compareFunction: function(a: mixed, b: mixed): Number): Array<number> source

import {argSort} from '@jsmlt/jsmlt/src/arrays/index.js'

Sort an array and return the array indices of the sorted elements. Corresponds to JavaScript's native Array.sort(), but instead of returning the sorted elements, it returns the indices of the sorted elements.

Params:

Name	Type	Attribute	Description
array	Array<mixed>		Array to be sorted
compareFunction	function(a: mixed, b: mixed): Number	optional default: null	Callback function be used for sorting. This function takes two array elements and returns an integer indicating sort order of the two elements a and b: < 0 : a before b == 0 : leave order of a and b unchanged with respect to each other > 0 : b after a Defaults to numeric sorting.

Return:

Array<number>

Array of array indices such that the elements corresponding with these indices in the original array are sorted

public auroc(yTrue: Array<number>, yPred: Array<mixed>): number source

import {auroc} from '@jsmlt/jsmlt/src/validation/metrics/index.js'

Calculate the area under the receiver-operator characteristic curve (AUROC) for a set of predictions. Area is calculated using the Trapezoidal rule.

Params:

Name	Type	Attribute	Description
yTrue	Array<number>		True labels. Must contain only integers 0 and 1
yPred	Array<mixed>		Predicted label confidences. Must be between 0 (fully confident in negative prediction) and 1 (fully confident in positive prediction), both inclusive

Return:

number

Calculated AUROC

public binaryIntervalSearch(array: Array<number>, value: number): number source

import {binaryIntervalSearch} from '@jsmlt/jsmlt/src/util/search/index.js'

Perform a binary search in a sorted array A to find the index i such that the search value is larger than or equal to A[i], and strictly smaller than A[i+1]. Informally, this corresponds with finding the interval in which the search value lies. Throws an error when the input value is outside of the array range. Does not check whether the array is actually sorted.

Params:

Name	Type	Attribute	Description
array	Array<number>		Sorted input array
value	number		Value for which the interval should be found

Return:

number

Index i of array element A[i] such that value >= A[i] && value < A[i + 1]

public concatenate(axis: number, S: ...Array<mixed>): Array source

import {concatenate} from '@jsmlt/jsmlt/src/arrays/index.js'

Concatenate two or more n-dimensional arrays.

Params:

Name	Type	Attribute	Description
axis	number		Axis to perform concatenation on
S	...Array<mixed>		Arrays to concatenate. They must have the same shape, except in the dimension corresponding to axis (the first, by default)

Return:

Array

Concatenated array

public dot(x: Array<number>, y: Array<number>): number source

import {dot} from '@jsmlt/jsmlt/src/arrays/index.js'

Calculate dot product of two vectors. Vectors should have same size.

Params:

Name	Type	Attribute	Description
x	Array<number>		First vector
y	Array<number>		Second vector

Return:

number

Dot product scalar result

public equal(array1: Array<mixed> | mixed, array2: Array<mixed> | mixed): boolean source

import {equal} from '@jsmlt/jsmlt/src/arrays/index.js'

Deep check whether two arrays are equal: sub-arrays will be traversed, and strong type checking is enabled.

Params:

Name	Type	Attribute	Description
array1	Array<mixed> \| mixed		First array to check or array element to check
array2	Array<mixed> \| mixed		Second array to check ot array element to check. Will be checked against first array

Return:

boolean

Whether the two arrays are the same

public fill(A: Array<mixed>, value: mixed): Array<mixed> source

import {fill} from '@jsmlt/jsmlt/src/arrays/index.js'

Set all entries in an array to a specific value and return the resulting array. Original array is not modified.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array of which entries should be changed
value	mixed		Value the array entries should be changed to

Return:

Array<mixed>

Array with modified entries

public flatten(A: Array<mixed>): Array<mixed> source

import {flatten} from '@jsmlt/jsmlt/src/arrays/index.js'

Recursively flatten an array.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to be flattened

Return:

Array<mixed>

Flattened array

public full(shape: Array<number>, value: mixed): Array<mixed> source

import {full} from '@jsmlt/jsmlt/src/arrays/index.js'

Initialize an n-dimensional array of a certain value.

Params:

Name	Type	Attribute	Description
shape	Array<number>		Array specifying the number of elements per dimension. n-th element corresponds to the number of elements in the n-th dimension.
value	mixed		Value to fill the array with

Return:

Array<mixed>

Array of the specified with zero in all entries

public getArrayElement(A: Array<mixed>, index: Array<number>): mixed source

import {getArrayElement} from '@jsmlt/jsmlt/src/arrays/index.js'

Get an arbitrary element from an array, using another array to determine the index inside the first array.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to get an element from
index	Array<number>		Indices to find array element. n-th element corresponds to index in n-th dimension

Return:

mixed

Array element value at index

public getShape(A: Array<mixed>): Array<number> source

import {getShape} from '@jsmlt/jsmlt/src/arrays/index.js'

Find the shape of an array, i.e. the number of elements per dimension of the array.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Arbitrarily nested array to find shape of.

Return:

Array<number>

Array specifying the number of elements per dimension. n-th element corresponds to the number of elements in the n-th dimension.

public getTouchCoordinate(e: object, coordinate: string): * source

import {getTouchCoordinate} from '@jsmlt/jsmlt/src/util/input-devices/index.js'

Get touch coordinate (x or y) from touchpad input.

Params:

Name	Type	Attribute	Description
e	object		Event
coordinate	string		Coordinate ("x" or "y", case insensitive)

Return:

public internalSum(A: Array<number>): number source

import {internalSum} from '@jsmlt/jsmlt/src/arrays/index.js'

Sum all elements of an array.

Params:

Name	Type	Attribute	Description
A	Array<number>		Array

Return:

number

Sum of all vector elements

public linspace(a: number, b: number, n: number): Array<number> source

import {linspace} from '@jsmlt/jsmlt/src/arrays/index.js'

Generate n points on the interval (a,b), with intervals (b-a)/(n-1).

Params:

Name	Type	Attribute	Description
a	number		Starting point
b	number		Ending point
n	number		Number of points

Return:

Array<number>

Array of evenly spaced points on the interval (a,b)

Example:

var list = linspace(1, 3, 0.5);
// list now contains [1, 1.5, 2, 2.5, 3]

public loadDatasetFromCSV(input: string, callback: function(X: Array<Array<number>>, y: Array<number>)) source

import {loadDatasetFromCSV} from '@jsmlt/jsmlt/src/datasets/index.js'

Load a dataset (features and target) from some CSV input string. Extracts the data from the CSV and uses all but the last column as the features and the last column as the target. This function is asynchronous, and needs a user callback for when the file is successfully parsed.

Params:

Name	Type	Attribute	Description
input	string		Input CSV string
callback	function(X: Array<Array<number>>, y: Array<number>)		Callback function with arguments X (features) and y (targets)

public loadDatasetFromRemoteCSV(url: string, callback: function(X: Array<Array<number>>, y: Array<number>)) source

import {loadDatasetFromRemoteCSV} from '@jsmlt/jsmlt/src/datasets/index.js'

Load a dataset from a remote CSV file. Fetches the CSV file and calls loadDatasetFromCSV. This function is asynchronous, and needs a user callback for when the remote CSV file is successfully loaded and parsed.

Params:

Name	Type	Attribute	Description
url	string		Input CSV file URL
callback	function(X: Array<Array<number>>, y: Array<number>)		Callback function with arguments X (features) and y (targets)

public loadIris(callback: function(X: Array<Array<number>>, y: Array<number>)) source

import {loadIris} from '@jsmlt/jsmlt/src/datasets/index.js'

Load the iris dataset. This is an asynchronous function: when the Iris dataset is loaded, a user-specified callback function is invoked, with the data set features array and the targets array as the first and second parameter, respectively.

For more information, see https://github.com/jsmlt/datasets/tree/master/iris

Params:

Name	Type	Attribute	Description
callback	function(X: Array<Array<number>>, y: Array<number>)		Callback function with arguments X (features) and y (targets). Called when the dataset is successfully loaded

Example:

Load the Iris dataset and run a Perceptron classifier on it

var datasets = require('@jsmlt/jsmlt/datasets');
var Perceptron = require('@jsmlt/jsmlt/supervised/linear/perceptron');

datasets.loadIris(function(X, y) {
  var clf = new Perceptron();
  clf.train(X, y);
});

public meshGrid(x: Array<number>, y: Array<number>): Array<Array<Array<number>>> source

import {meshGrid} from '@jsmlt/jsmlt/src/arrays/index.js'

Generate a mesh grid, i.e. two m-by-n arrays where m=|y| and n=|x|, from two vectors. The mesh grid generates two grids, where the first grid repeats x row-wise m times, and the second grid repeats y column-wise n times. Can be used to generate coordinate grids.

Example input: x=[0, 1, 2], y=[2, 4, 6, 8] Corresponding output: matrix 1: [[0, 1, 2], [0, 1, 2], [0, 1, 2], [0, 1, 2]] matrix 2: [[2, 2, 2], [4, 4, 4], [6, 6, 6], [8, 8, 8]]

Params:

Name	Type	Attribute	Description
x	Array<number>		Vector of x-coordinates
y	Array<number>		Vector of y-coordinates

Return:

Array<Array<Array<number>>>

Two-dimensional array containing the x-grid as the first element, and the y-grid as the second element

public norm(x: Array<number>): * source

import {norm} from '@jsmlt/jsmlt/src/arrays/index.js'

Calculate the Euclidian norm of a vector.

Params:

Name	Type	Attribute	Description
x	Array<number>		Vector of which to calculate the norm

Return:

public pad(A: Array<mixed>, paddingLengths: Array<number>|Array<Array.<number>>, paddingValues: Array<number>|Array<Array.<number>>, axes: Array<number>): Array<mixed> source

import {pad} from '@jsmlt/jsmlt/src/arrays/index.js'

Pad an array along one or multiple axes.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to be padded
paddingLengths	Array<number>\|Array<Array.<number>>		Amount of padding for each axis that should be padded. Each element in this array should be a two-dimensional array, where the first element specifies the padding at the start (front) of the axis, and the second element specifies the padding at the end (back) of the axis. The nth element of `paddingLength` specifies the front and back padding of the nth axis in the `axes` parameter
paddingValues	Array<number>\|Array<Array.<number>>		The values to pad each axis with. See the specification of the `paddingLenghts` parameter for the expected structure
axes	Array<number>	optional	Indices of axes to be padded. Defaults to the first n axes, where n is the number of elements in `paddingLengths`

Return:

Array<mixed>

Padded array

public permuteAxes(A: Array<mixed>, newAxes: Array<number>): Array<mixed> source

import {permuteAxes} from '@jsmlt/jsmlt/src/arrays/index.js'

Permute the axes of an input array. In other words, you can interchange the axes of an n-dimensional input array.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array of which the axes should be permuted
newAxes	Array<number>		For the i-th element of this array, specify the index of the axis in the original array that should be used

Return:

Array<mixed>

Array with permuted axes

public power(A: Array<mixed>, y: number | Array<number>): Array<mixed> source

import {power} from '@jsmlt/jsmlt/src/arrays/index.js'

Raise all elements in an array to some power. The power to raise the elements to can either be the same number for all elements, in which case it should be passed as a number, or an individual number for all elements, in which case it should be passed as an array of the same shape as the input array.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Input array
y	number \| Array<number>		The power to raise all elements to. Either a {number} (all elements will be raised to this power) or an array (elements in the input array will be raised to the power specified at the same position in the powers array)

Return:

Array<mixed>

Array containing the input elements, raised to the specified power

public rand(a: number, b: number): number source

import {rand} from '@jsmlt/jsmlt/src/random/index.js'

Generate a random number between a lower bound (inclusive) and an upper bound (exclusive).

Params:

Name	Type	Attribute	Description
a	number		Lower bound (inclusive)
b	number		Upper bound (exclusive)

Return:

number

Random number in range [a,b)

public randint(a: number, b: number, shape: number | Array<number>): number | Array<mixed> source

import {randint} from '@jsmlt/jsmlt/src/random/index.js'

Generate a random integer between a lower bound (inclusive) and an upper bound (exclusive).

Params:

Name	Type	Attribute	Description
a	number		Lower bound (inclusive)
b	number		Upper bound (exclusive)
shape	number \| Array<number>	optional default: null	If null, a single element is returned. If integer, an array of {shape} elements is returned. If an Array, random numbers are returned in a shape specified by this array. n-th element corresponds to the number of elements in the n-th dimension.

Return:

number | Array<mixed>

Random integer in range [a,b), or a possibly nested array of random integers in range [a, b)

public repeat(axis: number, numRepeats: number, A: Array<mixed>): Array<mixed> source

import {repeat} from '@jsmlt/jsmlt/src/arrays/index.js'

Repeat an array multiple times along an axis. This is essentially one or more concatenations of an array with itself.

Params:

Name	Type	Attribute	Description
axis	number		Axis to perform repetition on
numRepeats	number		Number of times to repeat the array
A	Array<mixed>		Array to repeat

Return:

Array<mixed>

Specified array repeated numRepeats times

public reshape(A: Array<mixed>, shape: Array<number>): Array<mixed> source

import {reshape} from '@jsmlt/jsmlt/src/arrays/index.js'

Reshape an array into a different shape.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to reshape
shape	Array<number>		Array specifying the number of elements per dimension. n-th element corresponds to the number of elements in the n-th dimension.

Return:

Array<mixed>

Reshaped array

public sample(input: Array<mixed>, number: number, withReplacement: boolean, weights: Array<number> | string): Array<mixed> source

import {sample} from '@jsmlt/jsmlt/src/random/index.js'

Take a random sample with or without replacement from an array. Supports using sampling weights, governing the probability of an item in the input array being selected.

Params:

Name	Type	Attribute	Description
input	Array<mixed>		Input array
number	number		Number of elements to sample from the input array
withReplacement	boolean	optional default: true	Whether to sample with (set to true) or without replacement (false)
weights	Array<number> \| string	optional default: 'uniform'	Weights to use for sampling. Defaults to 'uniform', which means all samples have equal probability of being selected. Alternatively, you can pass an array of weights, containing a single weight for each element in the input array

Return:

Array<mixed>

Array of length {number} with values sampled from the input array

public sampleFisherYates(input: Array<mixed>, number: number): Array<mixed> source

import {sampleFisherYates} from '@jsmlt/jsmlt/src/random/index.js'

Take a random sample without replacement from an array. Uses the Fisher-Yates shuffling, algorithm, modified to accomodate sampling.

Params:

Name	Type	Attribute	Description
input	Array<mixed>		Input array
number	number		Number of elements to sample from the input array

Return:

Array<mixed>

Array of length {number} with values sampled from the input array

public scale(A: Array<mixed>, c: number): Array<mixed> source

import {scale} from '@jsmlt/jsmlt/src/arrays/index.js'

Multiply each element of an array by a scalar (i.e. scale the array).

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to scale
c	number		Scalar

Return:

Array<mixed>

Scaled array

public setArrayElement(A: Array<mixed>, index: Array<number>, value: mixed): * source

import {setArrayElement} from '@jsmlt/jsmlt/src/arrays/index.js'

Set an arbitrary element in an array, using another array to determine the index inside the array.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to set an element in
index	Array<number>		Indices to find array element. n-th element corresponds to index in n-th dimension
value	mixed		New element value at index

Return:

public shuffle(S: ...Array<mixed>): Array<Array<mixed>> source

import {shuffle} from '@jsmlt/jsmlt/src/arrays/index.js'

Randomly shuffle multiple arrays in the primary (first) axis. All input arrays are shuffled simultaneously, i.e., if an element with index i is moved to index j for the first array, the the same happens for the second (and third, etc.) array.

Params:

Name	Type	Attribute	Description
S	...Array<mixed>		Arrays to shuffle. They must have the same size in the primary axis

Return:

Array<Array<mixed>>

Shuffled matrices

public slice(A: Array<mixed>, start: Array<number>, stop: Array<number>): Array<mixed> source

import {slice} from '@jsmlt/jsmlt/src/arrays/index.js'

Take a slice out of an input array. Negative indices can be used in both the starting indices and the stopping indices. Negative indices: the negative stopping index is used as the negative offset relative to the last index in the particular dimension.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to extract block from
start	Array<number>		Array specifying the starting index per dimension. n-th element corresponds to the number of elements to skip, before extracting the block, in the n-th dimension. Negative indices are supported.
stop	Array<number>		Array specifying the index to stop at (exclusive) per dimension. n-th element corresponds to the stopping index in the n-th dimension. Negative indices are supported. Use null for unlimited offset.

Return:

Array<mixed>

Array slice extracted from input array

public subBlock(A: Array<mixed>, offset: Array<number>, shape: Array<number>): Array<mixed> source

import {subBlock} from '@jsmlt/jsmlt/src/arrays/index.js'

this function was deprecated. Use slice() instead

Extract a sub-block of a matrix of a particular shape at a particular position.

Params:

Name	Type	Attribute	Description
A	Array<mixed>		Array to extract block from
offset	Array<number>		Array specifying the offset per dimension. n-th element corresponds to the number of elements to skip, before extracting the block, in the n-th dimension.
shape	Array<number>		Array specifying the number of elements per dimension. n-th element corresponds to the number of elements in the n-th dimension.

Return:

Array<mixed>

Sub-block extracted from array

public sum(S: ...Array<mixed>): Array<mixed> source

import {sum} from '@jsmlt/jsmlt/src/arrays/index.js'

Calculate element-wise sum of two or more arrays. Arrays should have the same shape.

Params:

Name	Type	Attribute	Description
S	...Array<mixed>		Arrays to concatenate. They must have the same shape

Return:

Array<mixed>

Sum of arrays

public trainTestSplit(input: Array<Array<mixed>>, optionsUser: Object): Array source

import {trainTestSplit} from '@jsmlt/jsmlt/src/model-selection/index.js'

Split a dataset into a training and a test set.

Params:

Name	Type	Attribute	Description
input	Array<Array<mixed>>		List of input arrays. The input arrays should have the same length (i.e., they should have the same first dimension size)
optionsUser	Object		User-defined options. See method implementation for details
optionsUser.trainSize	number	optional default: 0.8	Size of the training set. If int, this exact number of training samples is used. If float, the total number of elements times the float number is used as the number of training elements

Return:

Array

List of output arrays. The number of elements is 2 times the number of input elements. For each input element, a pair of output elements is returned.

Example:

Example with n=5 datapoints and d=2 features per sample

// n x d array of features
var X = [[0, 0], [0.5, 0.2], [0.3, 2.5], [0.8, 0.9], [0.7, 0.2]];

// n-dimensional array of labels
var y = [1, 0, 0, 1, 1]; // n-dimensional array of labels

// Split into training and test set
var [X_train, y_train, X_test, y_test] = trainTestSplit([X, y], {trainSize: 0.8});

// Now, X_train and y_train will contain the features and labels of the training set,
// respectively, and X_test and y_test will contain the features and labels of the test set.

// Depending on the random seed, the result might be the following
X_train: [[0, 0], [0.5, 0.2], [0.3, 2.5], [0.7, 0.2]]
y_train: [1, 0, 0, 1]
X_test:  [[0.8, 0.9]]
y_test:  [1]

public transpose(A: Array<Array<number>>): Array<Array<number>> source

import {transpose} from '@jsmlt/jsmlt/src/arrays/index.js'

Get the transpose of a matrix or vector.

Params:

Name	Type	Attribute	Description
A	Array<Array<number>>		Matrix or vector

Return:

Array<Array<number>>

Transpose of the matrix

public unique(array: Array<mixed>): Array<mixed> source

import {unique} from '@jsmlt/jsmlt/src/arrays/index.js'

Get unique elements in array

Params:

Name	Type	Attribute	Description
array	Array<mixed>		Input array

Return:

Array<mixed>

Array consisting of all unique elements in the input array

public valueCounts(array: Array<mixed>): Array<Array<mixed>> source

import {valueCounts} from '@jsmlt/jsmlt/src/arrays/index.js'

Count the occurrences of the unique values in an array

Params:

Name	Type	Attribute	Description
array	Array<mixed>		Input array

Return:

Array<Array<mixed>>

Array where each element is a 2-dimensional array. In these 2D arrays, the first element corresponds to the unique array value, and the second elements corresponds to the number of times this value occurs in the original array

public valueVector(n: number, value: mixed): * source

import {valueVector} from '@jsmlt/jsmlt/src/arrays/index.js'

Initialize a vector of a certain length with a specific value in each entry.

Params:

Name	Type	Attribute	Description
n	number		Number of elements in the vector
value	mixed		Value to initialize entries at

Return:

*	Array Vector of n elements of the specified value

public wrapSlice(array: Array<mixed>, begin: number, end: number): Array<mixed> source

import {wrapSlice} from '@jsmlt/jsmlt/src/arrays/index.js'

Take a slice out of an array, but wrap around the beginning an end of the array. For example, if begin is -1, the last element of the input array is used as the first output element.

Params:

Name	Type	Attribute	Description
array	Array<mixed>		Input array
begin	number		Index of first array element
end	number		Index of end of slice range (element with this index will itself not be included in output)

Return:

Array<mixed>

Sliced array

public zeros(shape: Array<number>): Array<mixed> source

import {zeros} from '@jsmlt/jsmlt/src/arrays/index.js'

Initialize an n-dimensional array of zeros.

Params:

Name	Type	Attribute	Description
shape	Array<number>		Array specifying the number of elements per dimension. n-th element corresponds to the number of elements in the n-th dimension.

Return:

Array<mixed>

Array of the specified with zero in all entries

public zipWithIndex(array: Array<mixed>): Array<Array<mixed>> source

import {zipWithIndex} from '@jsmlt/jsmlt/src/arrays/index.js'

From an input array, create a new array where each element is comprised of a 2-dimensional array where the first element is the original array entry and the second element is its index

Params:

Name	Type	Attribute	Description
array	Array<mixed>		Input array

Return:

Array<Array<mixed>>

Output array