enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Feature hashing - Wikipedia

    en.wikipedia.org/wiki/Feature_hashing

    Let us take the output feature vector dimension (N) to be 4. Then output x will be [0,2,1,0]. It has been suggested that a second, single-bit output hash function ξ be used to determine the sign of the update value, to counter the effect of hash collisions. [2] If such a hash function is used, the algorithm becomes

  3. Pearson hashing - Wikipedia

    en.wikipedia.org/wiki/Pearson_hashing

    A workaround to this is to use a simple permutation function instead of a table stored in program memory. However, using a too simple function, such as T[i] = 255-i, partly defeats the usability as a hash function as anagrams will result in the same hash value; using a too complex function, on the other hand, will affect speed negatively. Using ...

  4. Hash function - Wikipedia

    en.wikipedia.org/wiki/Hash_function

    The Python hash is still a valid hash function when used within a single run, but if the values are persisted (for example, written to disk), they can no longer be treated as valid hash values, since in the next run the random value might differ.

  5. List of hash functions - Wikipedia

    en.wikipedia.org/wiki/List_of_hash_functions

    Fowler–Noll–Vo hash function (FNV Hash) 32, 64, 128, 256, 512, or 1024 bits xor/product or product/XOR Jenkins hash function: 32 or 64 bits XOR/addition Bernstein's hash djb2 [2] 32 or 64 bits shift/add or mult/add or shift/add/xor or mult/xor PJW hash / Elf Hash: 32 or 64 bits add,shift,xor MurmurHash: 32, 64, or 128 bits product/rotation ...

  6. Fast Walsh–Hadamard transform - Wikipedia

    en.wikipedia.org/wiki/Fast_Walsh–Hadamard...

    Python example code [ edit ] import math def fwht ( a ) -> None : """In-place Fast Walsh–Hadamard Transform of array a.""" assert math . log2 ( len ( a )) . is_integer (), "length of a is a power of 2" h = 1 while h < len ( a ): # perform FWHT for i in range ( 0 , len ( a ), h * 2 ): for j in range ( i , i + h ): x = a [ j ] y = a [ j + h ] a ...

  7. Locality-sensitive hashing - Wikipedia

    en.wikipedia.org/wiki/Locality-sensitive_hashing

    In computer science, locality-sensitive hashing (LSH) is a fuzzy hashing technique that hashes similar input items into the same "buckets" with high probability. [1] ( The number of buckets is much smaller than the universe of possible input items.) [1] Since similar items end up in the same buckets, this technique can be used for data clustering and nearest neighbor search.

  8. Linear probing - Wikipedia

    en.wikipedia.org/wiki/Linear_probing

    Linear probing is a component of open addressing schemes for using a hash table to solve the dictionary problem.In the dictionary problem, a data structure should maintain a collection of key–value pairs subject to operations that insert or delete pairs from the collection or that search for the value associated with a given key.

  9. Fowler–Noll–Vo hash function - Wikipedia

    en.wikipedia.org/wiki/Fowler–Noll–Vo_hash...

    Fowler–Noll–Vo (or FNV) is a non-cryptographic hash function created by Glenn Fowler, Landon Curt Noll, and Kiem-Phong Vo.. The basis of the FNV hash algorithm was taken from an idea sent as reviewer comments to the IEEE POSIX P1003.2 committee by Glenn Fowler and Phong Vo in 1991.