MATLAB Function Reference |

**Syntax**

**Description**

```
B = sum(A)
```

returns sums along different dimensions of an array.

If `A`

is a vector, `sum(A)`

returns the sum of the elements.

If `A`

is a matrix, `sum(A)`

treats the columns of `A`

as vectors, returning a row vector of the sums of each column.

If `A`

is a multidimensional array, `sum(A)`

treats the values along the first non-singleton dimension as vectors, returning an array of row vectors.

```
B = sum(A,dim)
```

sums along the dimension of `A`

specified by scalar `dim`

.

**Remarks**

`sum(diag(X))`

is the `trace`

of `X`

.

**Examples**

The magic square of order 3 is

This is called a magic square because the sums of the elements in each column are the same.

as are the sums of the elements in each row, obtained by transposing:

** See Also**

subvolume | superiorto |