Given a finite number of vectors x 1 , x 2 , … , x n {\displaystyle x_{1},x_{2},\dots ,x_{n}} in a real vector space, a conical combination, conical sum, or weighted sum of these vectors is a vector of the form
where α i {\displaystyle \alpha _{i}} are non-negative real numbers.
The name derives from the fact that the set of all conical sum of vectors defines a cone (possibly in a lower-dimensional subspace).