MATLAB Function Reference |

Replace nonzero sparse matrix elements with ones

**Syntax**

**Description**

```
R = spones(S)
```

generates a matrix `R`

with the same sparsity structure as `S`

, but with `1`

's in the nonzero positions.

**Examples**

`c`

`=`

`sum(spones(S))`

is the number of nonzeros in each column.

`r`

`=`

`sum(spones(S'))'`

is the number of nonzeros in each row.

`sum(c)`

and `sum(r)`

are equal, and are equal to `nnz(S)`

.

**See Also**

spline | spparms |