unit vector
Noun
Meaning
unit vector (plural unit vectors)
(linear algebra, mathematical analysis) A vector with the length of 1, defined as
u
^
=
u
‖
u
‖
{\displaystyle \mathbf {\hat {u}} ={\frac {\mathbf {u} }{\|\mathbf {u} \|}}}
.
Examples
Acceleration vector seeAlso From the heliocentric point of view consider the vector to the planet where is the distance to the planet and is a unit vector pointing towards the planet.
I is defined picking the unit vector that maximizes the flow around the point, because the true flow is maximized across the disk that is perpendicular to it.
Here, the imaginary unit is the (four-dimensional) volume element, and is the unit vector in time direction.
More precisely, when H is differentiable, the dot product of the gradient of H with a given unit vector is equal to the directional derivative of H in the direction of that unit vector.
Also length of a unit vector (of dimension length, not length/force, etc.) has no coordinate-system-invariant significance.
Often this is done to turn the problem into the computation of a directional derivative in the direction of a unit vector.