Geodesics estimated using the heat method applied to $G★$ are close to the ground truth (top). Other kernels yield suboptimal results for most choices of $k$ (bottom); in particular, notice how the tip of the tail is usually inferred to be closer than it should (due to its being directly connected to the body in the underlying graph; see Figure 24). Yellow points are closer to the source (marked with an arrow in the ground truth plot).