asum

Purpose

Computes the sum across one dimension of an N-dimensional array.

Format

y = asum(x, dim)

Parameters:

• x (N-dimensional array)

• dim (scalar) – the dimension across which to sum.

Returns:

y (N-dimensional array)

Examples

x = seqa(1, 1, 24);

dims = { 2, 3, 4 };
x = areshape(x, dims);

y = asum(x, 3);

x is a 2x3x4 array, such that:

Plane [1,.,.]

   1.000    2.000    3.000    4.000
   5.000    6.000    7.000    8.000
   9.000   10.000   11.000   12.000

Plane [2,.,.]

  13.000   14.000   15.000   16.000
  17.000   18.000   19.000   20.000
  21.000   22.000   23.000   24.000

and y is equal to:

Plane [1,.,.]

  14.000   16.000   18.000   20.000
  22.000   24.000   26.000   28.000
  30.000   32.000   34.000   36.000

y = asum(x,1);

Using the same array x as the above example, this example computes the sum across the first dimension. y will be a 2x3x1 array, such that:

Plane [1,.,.]

  10.000
  26.000
  42.000

Plane [2,.,.]

  58.000
  74.000
  90.000

Remarks

The output y, will have the same sizes of dimensions as x, except that the dimension indicated by dim will be collapsed to 1.

See also

Functions amean()