﻿ indices – Algosim documentation
Algosim documentation: indices

# indices

Finds the indicies of a value in an ordered container.

## Syntax

• `indices(X, x)`

• `X` is an ordered container

• `x` is any object

• `indices(X, x, ε)`

• `X` is an ordered container

• `x` is any object

• `ε` is a non-negative integer

## Description

If `X` is an ordered container and `x` any value, then `indices(X, x)` returns the list containing the the 1-based indices of the occurrences of `x` in `X`.

`index(X, x, ε)` has the same behaviour, but it compares floating-point values with epsilon `ε` if `ε > 0`; if `ε = 0`, a default, non-zero, epsilon is used.

## Examples

`Alice ≔ ExampleData("Alice in Wonderland");`
`indices(words(Alice) @ LowerCase, "music")`
```14243
19926
19968
```
`indices(words(Alice) @ LowerCase, "song")`
```11998
14430
21051
21398
22177
22180
22362
```
`A ≔ SequenceVector(10) ⊗ SequenceVector(10)`
```⎛  1    2    3    4    5    6    7    8    9   10⎞
⎜  2    4    6    8   10   12   14   16   18   20⎟
⎜  3    6    9   12   15   18   21   24   27   30⎟
⎜  4    8   12   16   20   24   28   32   36   40⎟
⎜  5   10   15   20   25   30   35   40   45   50⎟
⎜  6   12   18   24   30   36   42   48   54   60⎟
⎜  7   14   21   28   35   42   49   56   63   70⎟
⎜  8   16   24   32   40   48   56   64   72   80⎟
⎜  9   18   27   36   45   54   63   72   81   90⎟
⎝ 10   20   30   40   50   60   70   80   90  100⎠
```
`indices(A, 50)`
```(5, 10)
(10, 5)
```