We have an C implementation of our algorithm Learning Prototypes and
Distances:
R.Paredes and E. Vidal. "Learning Prototypes and Distances: a prototype
reduction technique based on nearest neighbor error minimization".
Pattern Recognition 39(2): 180-188.
You can download it an see details at:
http://www.dsic.upv.es/~rparedes/english/research/LPD/index.html
Regards,
Roberto Paredes