# ind2vec

Convert indices to vectors

## Syntax

``vec = ind2vec(ind)``
``vec = ind2vec(ind,N)``

## Description

example

````vec = ind2vec(ind)` takes a row vector of indices, `ind`, and returns a sparse matrix of vectors, `vec`, containing a `1` in the row of the index they represent, as indicated by `ind`.`ind2vec` and `vec2ind` allow indices to be represented either by themselves, or as vectors containing a 1 in the row of the index they represent.```

example

````vec = ind2vec(ind,N)` returns an `N`-by-`M` sparse matrix, where `N` can be equal to or greater than the maximum index.```

## Examples

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This example shows how to convert indices to vector representation using the `ind2vec` function.

Define four indices and then convert them to vector representation.

```ind = [1 3 2 3]; vec = ind2vec(ind)```
```vec = (1,1) 1 (3,2) 1 (2,3) 1 (3,4) 1```

This example shows how to convert a vector to indices and back, using both the `ind2vec` and `vec2ind` functions.

Define a vector with all zeros in the last row and convert it to indices.

```vec = [0 0 1 0; 1 0 0 0; 0 1 0 0]' [ind,n] = vec2ind(vec)```
```vec = 0 1 0 0 0 1 1 0 0 0 0 0 ind = 3 1 2 n = 4```

Convert the indices to vector, while preserving the number of rows.

`vec2 = full(ind2vec(ind,n))`
```vec2 = 0 1 0 0 0 1 1 0 0 0 0 0```

## Input Arguments

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Indices, specified as a row vector.

Number of rows of the output matrix, specified as a scalar.

## Output Arguments

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Vector representation of the indices, returned as an `N`-by-`M` sparse matrix.

## Version History

Introduced before R2006a