Top Definition
A trajectory is the path a moving object follows through space as a function of time.

In control theory a trajectory is a time-ordered set of states of a dynamical system (see e.g. Poincaré map). In discrete mathematics, a trajectory is a sequence (f^k(x))_{k \in \mathbb{N}} of values calculated by the iterated application of a mapping f to an element x of its source.
The object might be a projectile or a satellite, for example. It thus includes the meaning of orbit—the path of a planet, an asteroid or a comet as it travels around a central mass. A trajectory can be described mathematically either by the geometry of the path, or as the position of the object over time.
by February 01, 2011
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