matlab - creating matrix with zero rows and one on index

Question

i have a vector `a = [1; 6; 8]` and want to create a matrix with `n` columns and `size(a,1)` rows. Each i'th row is all zeros but on the `a(i)` index is one. `>> make_the_matrix(a, 10)` ``` ans = 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 ```

Accepted Answer

use `sparse`

```
 numCol = 10; % number of colums in output matrix, should not be greater than max(a)
 mat = sparse( 1:numel(a), a, 1, numel(a), numCol );
```

if you want a full matrix just use

```
 full(mat)
```

matlab - creating matrix with zero rows and one on index

Solution

Problem