mathjs/docs/reference/functions/index.md

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Function index #

Create an index. An Index can store ranges having start, step, and end for multiple dimensions. Matrix.get, Matrix.set, and math.subset accept an Index as input.

Syntax #

math.index(range1, range2, ...)

Where #

• A number
• A string for getting/setting an object property
• An instance of Range
• A one-dimensional Array or a Matrix with numbers

Parameters #

Parameter	Type	Description
ranges	...*	Zero or more ranges or numbers.

Returns #

Type	Description
Index	Returns the created index

Examples #

const b = [1, 2, 3, 4, 5]
math.subset(b, math.index([1, 2, 3]))     // returns [2, 3, 4]

const a = math.matrix([[1, 2], [3, 4]])
a.subset(math.index(0, 1))             // returns 2

See also #

bignumber, boolean, complex, matrix, number, string, unit