Function Reference
— Built-in Function: sumsq (x, dim)

Sum of squares of elements along dimension dim. If dim is omitted, it defaults to 1 (column-wise sum of squares).

As a special case, if x is a vector and dim is omitted, return the sum of squares of the elements.

This function is conceptually equivalent to computing

          sum (x .* conj (x), dim)

but it uses less memory and avoids calling conj if x is real.