mathjs/docs/reference/functions/index.md

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

Each range can be any of:

Parameters

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

Returns

Type	Description
Index	Returns the created index

Examples

var math = math.js

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

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

See also

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