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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 b = [1, 2, 3, 4, 5]
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40 | math.subset(b, math.index([1, 2, 3])) // returns [2, 3, 4]
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41 |
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42 | const a = math.matrix([[1, 2], [3, 4]])
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43 | a.subset(math.index(0, 1)) // returns 2
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44 | ```
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45 |
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46 |
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47 | ## See also
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48 |
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49 | [bignumber](bignumber.md),
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50 | [boolean](boolean.md),
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51 | [complex](complex.md),
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52 | [matrix](matrix.md),
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53 | [number](number.md),
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54 | [string](string.md),
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55 | [unit](unit.md)
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