A conical combination of vectors v1,,vmv_1,\ldots,v_m in a real vector space is a

j=1majvj,aj0.\sum_{j=1}^m a_jv_j,\qquad a_j\ge0.

The coefficients need not sum to one. The empty combination is zero.

Comparison with convex combinations

If s=jaj>0s=\sum_j a_j>0, the combination is ss times the convex combination j(aj/s)vj\sum_j(a_j/s)v_j. Nonnegative coefficients may include zeros; strictly positive coefficients specify a smaller set of representations when generators are fixed.

References