Definition
Isomapis a non-linear dimensional reduction method that aims to preserve the intrinsic geometry of high-dimensional data in a lower-dimensional space. The main idea of isomap is to approximate the geodesic distances between data points on a manifold, rather than just using straight-line Euclidean distances.
Algorithm
- Determine the neighbors of each point
- All points in some fixed radius
- k-nearest neighbors
- Construct a neighborhood distnace graph
- Compute the shortest path between two nodes with Dijkstra’s algorithm.