linalg:mean

(linalg:mean array &optional axis keepdims)

Returns the arithmetic mean of every element: the linalg:sum divided by the linalg:size. Like a reduction in numpy, the result follows the element type: a packed double-float array (anything built by a linalg constructor) gives a double, while a plain integer array gives an exact rational.

With an integer axis (negative counts from the end) it averages along that axis instead, following exactly the axis and keepdims rules of linalg:sum: the axis is dropped from the result (kept with extent 1 under a non-nil keepdims), and a vector without keepdims reduces to the scalar itself.