# symmetricaldifference(Tvector3_double,Tvector3_double):Tvector3_double

Calculate the external product of two three-dimensional vectors

## Declaration

Source position: matrix.pp line 404

## Description

This operator returns the external product of two three dimensional vector. It is a vector orthonormal to the two multiplied vectors. The length of that vector is equal to the surface area of a parallelogram with the two vectors as sides.

The external product is often used to get a vector orthonormal to two other vectors, but of a predefined length. In order to do so, the result vector from the external product, is divided by its length, and then multiplied by the desired size.