Awesome! Thanks a lot. On Jun 19, 5:00 pm, Mensanator <[EMAIL PROTECTED]> wrote: > On Jun 19, 6:27 pm, godavemon <[EMAIL PROTECTED]> wrote: > > > > > I need to calculate the Hamming Distance of two integers. The hamming > > distance is the number of bits in two integers that don't match. I > > thought there'd be a function in math or scipy but i haven't been able > > to find one. This is my function but it seems like there should be a > > faster way. I do this computation many times and speed up is > > important. > > > def hamdist( a, b , bits = 32): > > def _hamdist( x, bits): > > if bits: > > return (x & 1) + _hamdist(x >> 1, bits-1) > > return x & 1 > > return _hamdist( a ^ b, bits) > > > Another alternative would be to convert the XOR to a binary string and > > count the # of 1's. > > > Which would be fastest? Are there better alternatives? > > Yep, use the gmpy module. > > >>> import gmpy > >>> help(gmpy.hamdist) > > Help on built-in function hamdist in module gmpy: > hamdist(...) > hamdist(x,y): returns the Hamming distance (number of bit- > positions > where the bits differ) between x and y. x and y must be mpz, or > else > get coerced to mpz. > > >>> gmpy.hamdist(15,6) > 2 > >>> gmpy.hamdist(2**177149,10**53330) > 61877 > >>> gmpy.hamdist(2**177149-1,10**53330) > > 115285 > > > > > Thanks!
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