Coordinate vector
In linear algebra, a coordinate vector is a representation of a vector as an ordered list of numbers that describes the vector in terms of a particular ordered basis. Coordinates are always specified relative to an ordered basis. Bases and their associated coordinate representations let one realize vector spaces and linear transformations concretely as column vectors, row vectors, and matrices, hence are useful in calculations.
The idea of a coordinate vector can also be used for infinite-dimensional vector spaces, as addressed below.
Let V be a vector space of dimension n over a field F and let
be an ordered basis for V. Then for every there is a unique linear combination of the basis vectors that equals v:
The coordinate vector of v relative to B is the sequence of coordinates
This is also called the representation of v with respect of B, or the B representation of v. The α-s are called the coordinates of v. The order of the basis becomes important here, since it determines the order in which the coefficients are listed in the coordinate vector.
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