Le contraire du simple n'est pas
le complexe, mais le faux.
André Comte-SponvilleA vector is a collection of numbers, arranged in a column or a row, which can be thought of as the coordinates of a point in n-dimensional space. Equipping vectors with sum and scalar multiplication allows us to define notions such as independence, span, subspaces, and dimension. Further, the scalar product introduces a notion of the angle between two vectors, and induces the concept of length, or norm. Via the scalar product, we can also view a vector as a linear function. We can compute the projection of a vector onto a line defined by another vector, onto a plane, or more generally onto a subspace. Projections can be viewed as a first elementary optimization problem (finding the point in a given set at minimum distance from a given point), and they constitute a basic ingredient in many processing and visualization techniques for high-dimensional data.
2.1 Vector basics
2.1.1 Vectors as collections of numbers
Vectors are a way to represent and manipulate a single collection of numbers. A vector x can thus be defined as a collection of elements x1, x2, …, xn, arranged in a column or in a row. We usually write vectors in column format:
Element xi is said to be the i-th component (or the i-th element, or entry) of vector x, and the number n of components is usually referred to as the dimension of x.
Review the options below to login to check your access.
Log in with your Cambridge Aspire website account to check access.
If you believe you should have access to this content, please contact your institutional librarian or consult our FAQ page for further information about accessing our content.