def car(n):
  return np.eye(n) - 1. / float(n)
Allows memory use to be reduced after much training by removing data
dataset/ETHPy150Open breuderink/eegtools/eegtools/spatfilt.py/car--crossover with--dataset/ETHPy150Open nltk/nltk/nltk/tokenize/punkt.py/PunktTrainer.freq_threshold