Python C extension to compute the permanent.
Nevar pievienot vairāk kā 25 tēmas Tēmai ir jāsākas ar burtu vai ciparu, tā var saturēt domu zīmes ('-') un var būt līdz 35 simboliem gara.

43 rindas
1.2KB

  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")