The expectation of the trends are one, which means, we suppose the COMPOSITION of asystem has inertia. Composition of a system tend to remain the same, even when the Sum changes. Thus, Composition is essential for the systems.

If we use three dimension of tree, shrubs, grasses to describe vegetation, then 3-2-1: 3-tree, 2-shrub, 1-grass is totally different vegetation from 1-2-3: 1-tree,2-shrubs, 3-grasses, even the total is 6 in both cases. And on the same time 30-20-10 is the same as 3-2-1.

A one inch photo is the same as an eight inches photo. Scalar multiplication will not essentially change systems.

This is very important, and essential for vegetation, and other natural resource sharing systems. So, we need a new kind of variables to describe both quantity and quality of a multi-systems. This kind of variable DOES EXIST.

On the other hand, Vectors are variables with Magnitude and Directions. And their directions are essential for vectors. Co-liners have the same projection on the unit hypersphere.