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| 2 |
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| 3 | # Function index
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| 4 |
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| 5 | Create an index. An Index can store ranges having start, step, and end
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| 6 | for multiple dimensions.
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| 7 | Matrix.get, Matrix.set, and math.subset accept an Index as input.
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| 8 |
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| 9 |
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| 10 | ## Syntax
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| 11 |
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| 12 | ```js
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| 13 | math.index(range1, range2, ...)
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| 14 | ```
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| 15 |
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| 16 | ### Where
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| 17 |
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| 18 | - A number
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| 19 | - A string for getting/setting an object property
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| 20 | - An instance of `Range`
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| 21 | - A one-dimensional Array or a Matrix with numbers
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| 22 |
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| 23 | ### Parameters
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| 24 |
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| 25 | Parameter | Type | Description
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| 26 | --------- | ---- | -----------
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| 27 | `ranges` | ...* | Zero or more ranges or numbers.
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| 28 |
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| 29 | ### Returns
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| 30 |
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| 31 | Type | Description
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| 32 | ---- | -----------
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| 33 | Index | Returns the created index
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| 34 |
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| 35 |
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| 36 | ## Examples
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| 37 |
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| 38 | ```js
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| 39 | const math = require('mathjs')
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| 40 |
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| 41 | const b = [1, 2, 3, 4, 5]
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| 42 | math.subset(b, math.index([1, 2, 3])) // returns [2, 3, 4]
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| 43 |
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| 44 | const a = math.matrix([[1, 2], [3, 4]])
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| 45 | a.subset(math.index(0, 1)) // returns 2
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| 46 | ```
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| 47 |
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| 48 |
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| 49 | ## See also
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| 50 |
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| 51 | [bignumber](bignumber.md),
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| 52 | [boolean](boolean.md),
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| 53 | [complex](complex.md),
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| 54 | [matrix](matrix.md),
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| 55 | [number](number.md),
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| 56 | [string](string.md),
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| 57 | [unit](unit.md)
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