Barycenter (source code)

= Barycenter
{title2=$a(b_\mu)=\int a\,d\mu\quad(a\text{ continuous affine})$}

= Barycentre
{synonym}

The <barycenter> of a <probability measure> on a compact convex set is the point satisfying the displayed affine integral identities. It exists by approximating the <measure> by finitely supported <measures> and using compactness of their finite convex combinations. It is unique because continuous affine <functions> separate points. In a Banach-space setting it agrees with the appropriate vector integral when that integral is defined.