Code for Isomap and PCA written in octave. It was done as an assignment problem (Dimensionality Reduction) as part of my coursework.
Refer: http://isomap.stanford.edu/ to know more about ISOMAP. This code is heavily influenced from their implementation.
You can start with main.m
Run: octave -q main.m swiss3D.txt
swiss3D.txt is an example dataset (Classic example used in ISOMAP)
Use at your own risk!