Fig. 2From: Time-dependent bag of words on manifolds for geodesic-based classification of video activities towards assisted living and healthcareExample of an n-sphere \(\mathcal {S}^{n}\) (n = 2) embedded in an (n + 1)-D space \(\mathbb {R}^{n~+~1}\). p and q are manifold points, i.e., \(\mathbf {p}, \mathbf {q} \in \mathcal {S}^{n}\). The geodesic ρ is the shortest curve between p and q on the manifoldBack to article page