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| | Hash table - Wikipedia, the free encyclopedia |
 | | In computer chess, a hash table is generally used to implement the transposition table. | | | In computer science, a hash table, or a hash map, is a data structure that associates keys with values. | | | Hash tables require the design of an effective hash function for each key type, which in many situations is more difficult and time-consuming to design and debug than the mere comparison function required for a self-balancing binary search tree. |
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http://en.wikipedia.org/wiki/Hash_table
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| | Hash function - Wikipedia, the free encyclopedia |
| | Consequently, the equality of two hash values does not guarantee the two inputs were the same, but in some cases, probability theoretic or computability theoretic guarantees apply. | | | Then compute the hash function again at the receiver, and if the hash values do not match, there was an error. | | | Typical hash functions have an infinite domain, such as byte strings of arbitrary length, and a finite range, such as bit sequences of some fixed length. |
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http://en.wikipedia.org/wiki/Hash_function
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| | Distributed hash table - definition of Distributed hash table in Encyclopedia |
| | Distributed hash tables (DHTs) are a class of decentralized, distributed systems and algorithms being developed to provide a scalable, self-configuring infrastructure with a clean programming interface. | | | Routing tables are used by DHT nodes to efficiently determine what other node is responsible for a given piece of data. | | | Distributed hash tables attempt to find a more optimal method for organizing nodes while still avoiding the problems of Napster. |
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http://encyclopedia.laborlawtalk.com/Distributed_hash_table
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| | The Hash Table Library |
| | Hashing was discovered and first published and implemented on computers in the early 1950s, and is based on a simple idea: transform the key to a number (the hash process), and then use that number to index a table. | | | Table creation and deletion have only very modest costs, so in practice, the cost of processing the data is likely to overwhelm that for storage and retrieval in dynamic hash tables, demonstrating the great efficiency of hashing. | | | Hash tables, sometimes also known as associative arrays, or scatter tables, are a data structure that offers fast lookup, insertion, and deletion of (key, value) pairs. |
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http://www.math.utah.edu/~beebe/software/hash/hash.html
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| | Chapter 3. Hash table |
| | Hash tables implement the data structure known as the dictionary. | | | Hash tables utilize hash functions to map the key of data inserted into the table into a more or less random index of the table. | | | While for large n it definitely is better to have constant rather than logarithmic or linear access time, for small n the time necessary to compute the hash function, traverse the list of entries mapped to a given index, and compare their keys to the one we are looking for is not insignificant. |
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http://bo.majewski.name/bluear/gnu/GLib/ch03.html
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| | The Main Transposition Table |
| | It's possible that this line of reasoning inspired early computer chess programmers, and this is in fact a minor reason to implement a transposition hash table. | | | Since many positions are apt to map to the same element in the hash table, the table elements contain a verification value, which can be used to make sure that the element in the table is the one that you are trying to find. | | | A transposition hash table can be used to detect these cases in order to avoid duplicating work. |
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http://www.seanet.com/~brucemo/topics/hashing.htm
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| | Library Procedures - Tcl_Hash manual page |
| | All of the keys in a given table have the same form, which is specified when the table is initialized. | | | If this flag is set then the hash table will attempt to rectify this by randomising the bits and then using the upper N bits as the index into the table. | | | There may be at most one entry in a hash table with a particular key, but many entries may have the same value. |
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http://www.tcl.tk/man/tcl8.4/TclLib/Hash.htm
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| | Hash Tables |
| | One way to create a table, either on disk or in main memory, is to use a hash table. | | | Since the idea in a hash table is to do a lookup by only looking at one location in the table, rehashing should be minimized as much as possible. | | | The idea is that a table is a place to store data records, each containing a key value as well as other data fields (or field), so as to easily retrieve the data later by supplying a key value. |
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http://cis.stvincent.edu/swd/hash/hash.html
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| | SparkNotes: Hash Tables: What is a Hash Table? |
| | The hash function is a mapping from the input space to the integer space that defines the indices of the array. | | | In other words, the hash function provides a way for assigning numbers to the input data such that the data can then be stored at the array index corresponding to the assigned number. | | | A hash function doesn't guarantee that every input will map to a different output (in fact, as we'll see in the next section, it shouldn't do this). |
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http://www.sparknotes.com/cs/searching/hashtables/section1.html
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| | A Hash Function for Hash Table Lookup |
| | If inlining is possible, the Rotating hash was the fastest acceptable hash, followed by Pearson or the Generalized CRC (if table lookup is OK) or One-at-a-Time (if table lookup is not OK). | | | If a hash allows small sets of input bits to cancel each other out, and the user keys differ in only those bits, then all keys will map to the same handful of hash values. | | | A common weakness in hash function is for a small set of input bits to cancel each other out. |
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http://burtleburtle.net/bob/hash/doobs.html
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| | The Hash Table |
| | First of all, the hash table is a form of content-addressable memory-with each chess board (a node in the chess tree) we wish to associate some slot in the table. | | | The hash table is a way of storing information about positions which have already been searched; if the same position is reached again, the search can be sped up or eliminated entirely by using this information. | | | Therefore, a hashing function h is required, which maps chess boards to slots in the table. |
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http://www.netlib.org/utk/lsi/pcwLSI/text/node346.html
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| | Tutorial - Intro to Hash Tables |
| | well mirc's interface for hash tables is alot like dealing associative arrays in some other languages as well as mappings in others. | | | used with just the name parameter, $hget returns the table name you specified if that table exists (that is if you /hmake-ed the table) otherwise it returns $null. | | | this is not a recommended way of saving your hash table as usually the item information is just as important as the data information. |
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http://www.mircscripts.org/showdoc.php?type=tutorial&id=123
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| | Sorted Linear Hash Table |
| | Hash table is a high performance data structure used for data look up. | | | The simple hash table implementation does not have the capability to expand its table size. | | | Recall earlier, key-value pairs are stored in an array of key-value lists. |
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http://www.concentric.net/~Ttwang/tech/sorthash.htm
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| | CLHS: System Class HASH-TABLE |
| | Hash tables provide a way of mapping any object (a key) to an associated object (a value). | | | The intent is that this mapping be implemented by a hashing mechanism, such as that described in Section 6.4 ``Hashing'' of The Art of Computer Programming, Volume 3 (pp506-549). | | | Section 18.1 (Hash Table Concepts), Section 22.1.3.13 (Printing Other Objects) |
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http://www.lisp.org/HyperSpec/Body/syscla_hash-table.html
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| | hash table |
| | Definition: A dictionary in which keys are mapped to array positions by hash functions. | | | Paul E. Black, "hash table", from Dictionary of Algorithms and Data Structures, Paul E. Black, ed., NIST. | | | Note: Complexity depends on the hash function and collision resolution scheme, but may be constant (Θ(1)) if the table is big enough or grows. |
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http://www.nist.gov/dads/HTML/hashtab.html
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| | Selecting Hash Table Size in Java |
| | The Java built-in hash table has an initial capacity that can be specified by the programmer. | | | Since Java's hash table expansion uses formula of 2n+1. | | | What does the Java library use as a default hash table size if you do not specify anything - is it 89? |
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http://www.cris.com/~Ttwang/tech/hashsize.htm
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| | CLHS: Function MAKE-HASH-TABLE |
| | Such decisions are implementation-dependent, and these values only hints from the programmer to the implementation, and the implementation is permitted to ignore them. | | | This information, taken together with the rehash-threshold, controls the approximate number of entries which it should be possible to insert before the table has to grow. | | | (setq table (make-hash-table)) => # (setf (gethash "one" table) 1) => 1 (gethash "one" table) => NIL, false (setq table (make-hash-table :test 'equal)) => # (setf (gethash "one" table) 1) => 1 (gethash "one" table) => 1, T (make-hash-table :rehash-size 1.5 :rehash-threshold 0.7) => # |
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http://www.lispworks.com/reference/HyperSpec/Body/f_mk_has.htm
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| | 2. The Hash Table Module |
| | Whenever you need a cache or an associative array that must be independent of a particular display pointer then you should use the generic hash table mechanism within L | | | The hash table mechanism makes reinventing the wheel unnecessary in almost every case. | | | 's hash tables grow as needed whenever new entries are added. |
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http://www.lesstif.org/InsideLessTif/node105.html
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| | A Hash Table |
| | The file after it (unique.c) is an example of how to use the hash table. | | | Here is my C code for a module for hash table lookup: | | | The files before those are the support files that I always use. |
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http://burtleburtle.net/bob/hash/hashtab.html
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| | Dictionary.com/hash coding |
| | The hash function usually depends on the table size so | | | if the table needs to be enlarged it must usually be | | | The Free On-line Dictionary of Computing, © 1993-2005 Denis Howe |
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http://dictionary.reference.com/search?q=hash%20coding
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| | CLHS: Function HASH-TABLE-TEST |
| | For the four standardized hash table test functions (see make-hash-table), the test value returned is always a symbol. | | | Should signal an error of type type-error if hash-table is not a hash table. | | | Returns the test used for comparing keys in hash-table. |
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http://www.lisp.org/HyperSpec/Body/fun_hash-table-test.html
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| | DHT (distributed hash table) |
| | The trick for the researchers is creating a "lookup" algorithm that allows the location of data to be found in a short series of steps. | | | Instead, each server has a partial list, or small routing table, of where data is stored in the system. | | | As in peer-to-peer networks, there is no central server in the system that contains a list of where all the data, or files in the cabinet, are located. |
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http://www.networkworld.com/details/805.html
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| | Re: Hash table keys? |
| | On Sun, Mar 28, 1999 at 02:16:21PM -0800, it occurred to Greg Badros to write: > How do I get at a list of the keys in a guile hash table? |
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http://sources.redhat.com/ml/guile/1999-03/msg00304.html
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| | Re: Hash table keys? |
| | Lauri Alanko writes: > On Sun, Mar 28, 1999 at 02:16:21PM -0800, it occurred to Greg Badros to write: > > How do I get at a list of the keys in a guile hash table? |
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http://sources.redhat.com/ml/guile/1999-03/msg00308.html
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| | RE: hash table |
| | It doesn't look like the MzScheme libraries have procedures for directly manipulating hash tables in C. But you can evaluate Scheme expressions in C that produce and otherwise manipulate hash tables. | | | > > How can I make a hash table and pass it to scheme function from within > embed- > ding C code? | | | You probably want to use primitives like scheme_eval_string() and scheme_apply(). |
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http://www.cs.utah.edu/plt/mailarch/plt-scheme-2002/msg00289.html
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| | Creating a Hash Table (Java Developers Almanac Example) |
| | Creating a Hash Table (Java Developers Almanac Example) | | | // Create a hash table Map map = new HashMap(); // hash table map = new TreeMap(); // sorted map // Add key/value pairs to the map map.put( | | | Automatically Removing an Unreferenced Element from a Hash Table |
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http://www.javaalmanac.com/egs/java.util/coll_HashTables.html?l=rel
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| | distributed hash table - OneLook Dictionary Search |
| | We found one dictionary with English definitions that includes the word distributed hash table: | | | Tip: Click on the first link on a line below to go directly to a page where "distributed hash table" is defined. |
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http://www.onelook.com/?loc=rescb&w=distributed+hash+table
(74 words)
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| | [No title] |
| | If this function is fed the *functions* :(CLHS "EQ"), :(CLHS "EQL"), :(CLHS "EQUAL") or :(CLHS "EQUALP") it will create a normal (built-in) hash table with that as a test function. | | | This is a *(Library) for generic hash tables. | | | The non-generic function MAKE-GENERIC-HASHTABLE is used for hash table creation. |
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http://www.cliki.net/genhash?source
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| | PlanetMath: good hash table primes |
| | This is version 6 of good hash table primes, born on 2002-08-21, modified 2004-02-24. | | | In the course of designing a good hashing configuration, it is helpful to have a list of prime numbers for the hash table size. | | | Using primes for hash tables is a good idea because it minimizes clustering in the hashed table. |
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http://planetmath.org/encyclopedia/GoodHashTablePrimes.html
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| | make-hash-table |
| | Creates and returns a new hash table which, in addition to the standard functionality, can have a user-defined test, a user-defined hash function, and be a weak hash table. | | | A designator for a function of one argument, which returns a hash value. | | | hash-function is not supplied, then the hash value is the same as would be used if |
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http://www.lispworks.com/documentation/lw43/LWRM/html/lwref-57.htm
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| | Berkeley DB Reference Guide: Hash table size |
| | When setting up the hash database, knowing the expected number of elements that will be stored in the hash table is useful. | | | This value can be used by the Hash access method implementation to more accurately construct the necessary number of buckets that the database will eventually require. | | | The anticipated number of elements in the hash table can be specified by calling the DB->set_h_nelem method. |
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http://www.sleepycat.com/docs/ref/am_conf/h_nelem.html
(128 words)
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| | Rebel 12 chess package - Lokasoft |
| | • Hash Table Usage : Column one, transpositions found for white in (K)ilobytes, Column 2 is for black, the third column is the percentage of the hash table that is filled. |
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http://www.lokasoft.nl/rebel12.htm
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| | hash_set<Key, HashFcn, EqualKey, Alloc> |
| | is a Hashed Associative Container that stores objects of type | | | 's members are defined in the Unique Hashed Associative Container and Simple Associative Container requirements. | | | Using this site means you accept its terms of use |
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http://www.sgi.com/tech/stl/hash_set.html
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| | REBEL DECADE 3.0 release notes |
| | Hash table of 512 Kb but on FRIDAY up to 120 Mb! | | | All screen items are flexible using drag and drop. |
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http://www.rebel.nl/decrel.htm
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