SimHash (EXALEAD CloudView Custom code SDK)

java.lang.Object
- com.exalead.gni.GNIObject
- - com.exalead.gni.GNINativeObject
  - - com.exalead.mot.components.SimHash

```
public class SimHash
extends com.exalead.gni.GNINativeObject
```
Implementation of the M. Charikar's document similarity hash. Maps high-dimensional vectors to small-sized fingerprints. Fast 64 bits version: - Document is splitted into tokens: - Each token is represented by its hash value; a traditonal hash function is used - A vector V of 64 integers is initialized to 0: - In a cycle for all token's hash values (h), vector V is updated: - ith element is decreased by token's weight if the ith bit of the hash h is 0, otherwise - ith element is increased by token's weight if the ith bit of the hash h is 1 - Finally, signs of elements of V corresponds to the bits of the final 64 bits fingerprint References: [1] Similarity Estimation Techniques from Rounding Algorithms, in Proceedings of the thiry-fourth annual ACM symposium on Theory of computing, ACM Press, 2002

Constructors
Constructor and Description
`SimHash()` Public constructor.

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addToken(java.lang.String token)` Adds a token to the list of token to be used for the simhash computation.
`void`	`clear()` Reset the computation of the simhash value.
`static int`	`compare(long fp1, long fp2)` Compare two hashes.
`long`	`compute()` Compute the simhash value.

Methods inherited from class com.exalead.gni.GNINativeObject
finalize, isNativeNull, nativeFinalize

Methods inherited from class com.exalead.gni.GNIObject
printInternalCppPointer

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Class SimHash