Python C extension to compute the permanent.
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  1. import os, sys
  2. import numpy as np
  3. import time
  4. from matplotlib import pyplot as plt
  5. from permanent import permanent
  6. import itertools as it
  7. def permanent(a):
  8. """ Slow way to compute the permanent """
  9. r = range(len(a))
  10. return sum([np.prod(a[r, p]) for p in it.permutations(r)])
  11. if __name__ == '__main__':
  12. maxtime=1
  13. dimensions=range(1,11)
  14. for (function, label) in zip((permanent, perm_ryser), ("C", "Python")):
  15. counts=[]
  16. for dimension in dimensions:
  17. print dimension
  18. real=np.random.uniform(-1, 1, dimension*dimension).reshape((dimension, dimension))
  19. imag=np.random.uniform(-1, 1, dimension*dimension).reshape((dimension, dimension))
  20. submatrix=real+1j*imag
  21. t=time.clock()
  22. n=0
  23. while time.clock()-t < maxtime:
  24. for i in range(5):
  25. function(submatrix)
  26. n+=5
  27. counts.append(n)
  28. plt.plot(dimensions, counts, ".-", label=label)
  29. plt.ylabel("Number of permanents per second")
  30. plt.xlabel("Dimension")
  31. plt.xlim(min(dimensions), max(dimensions))
  32. plt.legend()
  33. plt.semilogy()
  34. plt.savefig("out.pdf")