LINEARITY
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1922 ▶ |
| Object type | General information, Methodology or model |
An arithmetical relation between quantities, i.e. characterized by a fixed arithmetic rate of increase or decrease.
y = ax, is a typical linear relation. Its representation is a straight line. It includes only variables of the first order or degree, affected by some arithmetic coefficient. It is merely accumulative at an invariable rate and corresponds to a permanent “one cause, one effect” process.
Linearity is a property of processes exempt of positive (accelerative), or negative (dampening) feedbacks. However, a positive or negative acceleration in itself can be linear, as derivation from a linear differential equation.
Truly linear processes are exceptional, even if during a limited span of time, a nonlinear one may look as linear. Trying to study nonlinear processes in linear terms is generally to no avail, as very few processes are immune to internal and/or external constraints expressed through regulation loops or controls. In such cases linear models may lead to gigantic (or subtle, which could be worse) extrapolation errors.