private ChainMap InitSimpleChainMapp()
{
ChainMap cm = new ChainMap() ;
cm.AddToChain(new ChainKey(new string[]{null, "word1"}), "valnull") ;
cm.AddToChain(new ChainKey(new string[]{"word1", "word2"}), "val1") ;
cm.AddToChain(new ChainKey(new string[]{"word2", "word3"}), "val2") ;
cm.AddToChain(new ChainKey(new string[]{"word1", "word2"}), "val3") ;
return cm ;
}
/// <summary>
/// Initializes word generator with random seed as parameter
/// </summary>
/// <param name="chains"></param>
/// <param name="rand"> Rng used if better randomness is desired. The default .NET Rng is
/// not completely random </param>
public WordGenerator(ChainMap chains, Random rand)
{
_chains = chains ;
if(rand != null)
{
_rand = rand ;
}
else
{
_rand = new Random() ;
}
Initialize() ;
}
/// <summary>
/// Initializes word generator with random seed as parameter
/// </summary>
/// <param name="chains"></param>
/// <param name="rand"> Rng used if better randomness is desired. The default .NET Rng is
/// not completely random </param>
public WordGenerator(ChainMap chains, Random rand)
{
_chains = chains;
if (rand != null)
{
_rand = rand;
}
else
{
_rand = new Random();
}
Initialize();
}
/// <summary>
/// Generate markov chains using input text
/// </summary>
public void GenerateChains()
{
//Split text
string[] splits = _text.Split();
List <string> advancedSplits = new List <string>();
foreach (string baseSplit in splits)
{
advancedSplits.AddRange(StringUtils.SplitAndKeep(baseSplit.ToLower(), _delims));
}
Chains = new ChainMap();
if (advancedSplits.Count < _chainSize * 2)
{
throw new Exceptions.InvalidArguments(string.Format("Chain size: {0} to small relative to text split {1}",
_chainSize, advancedSplits.Count));
}
//Insert null elements in the beginning so chains are created for the first _chainSize elements
for (int i = 0; i < _chainSize; i++)
{
advancedSplits.Insert(0, null);
}
List <string> .Enumerator listEnum = advancedSplits.GetEnumerator();
string[] chainWords = new string[_chainSize];
for (int i = 0; i < _chainSize; i++)
{
listEnum.MoveNext();
chainWords[i] = listEnum.Current;
}
while (listEnum.MoveNext())
{
string current = listEnum.Current;
ChainKey currKey = new ChainKey(chainWords);
Chains.AddToChain(currKey, current);
for (int i = 0; i < _chainSize - 1; i++)
{
chainWords[i] = chainWords[i + 1];
}
chainWords[_chainSize - 1] = current;
}
}
/// <summary>
/// Generate markov chains using input text
/// </summary>
public void GenerateChains()
{
//Split text
string[] splits = _text.Split() ;
List<string> advancedSplits = new List<string>() ;
foreach(string baseSplit in splits)
{
advancedSplits.AddRange(StringUtils.SplitAndKeep(baseSplit.ToLower(), _delims)) ;
}
Chains = new ChainMap() ;
if(advancedSplits.Count < _chainSize * 2)
{
throw new Exceptions.InvalidArguments(string.Format("Chain size: {0} to small relative to text split {1}",
_chainSize, advancedSplits.Count)) ;
}
//Insert null elements in the beginning so chains are created for the first _chainSize elements
for(int i = 0 ; i < _chainSize ; i++)
{
advancedSplits.Insert(0, null) ;
}
List<string>.Enumerator listEnum = advancedSplits.GetEnumerator() ;
string[] chainWords = new string[_chainSize] ;
for(int i = 0 ; i < _chainSize ; i++)
{
listEnum.MoveNext();
chainWords[i] = listEnum.Current ;
}
while(listEnum.MoveNext())
{
string current = listEnum.Current;
ChainKey currKey = new ChainKey(chainWords) ;
Chains.AddToChain(currKey, current) ;
for(int i = 0 ; i < _chainSize - 1 ; i++)
{
chainWords[i] = chainWords[i+1] ;
}
chainWords[_chainSize - 1] = current ;
}
}
private ChainKey[] CreateKeysArray(ChainMap map, Predicate <ChainKey> keyCondition)
{
List <ChainKey> newKeys = new List <ChainKey>();
List <ChainKey> origKeys = map.GetAllKeys();
foreach (ChainKey origKey in origKeys)
{
if (keyCondition.Invoke(origKey))
{
//Add key multiple times to ensure probability of picking it is proportional to the
//number of values
foreach (string val in map.GetValues(origKey))
{
newKeys.Add(origKey);
}
}
}
return(newKeys.ToArray());
}
/// <summary>
/// Get subchain of chainkeys and words that satisfies the passed in condition
/// </summary>
/// <param name="condition"></param>
/// <returns></returns>
internal ChainMap GetSubChain(ChainCondition condition)
{
//If conditions won't be applied return original chains
if (condition == null || condition == _alwaysTrueCondition ||
(condition.WordCondition == null && condition.KeyCondition == null))
{
return(_chains);
}
ChainMap newMap = new ChainMap();
bool valuesFound = false;
foreach (ChainKey key in _chains.GetAllKeys())
{
if (condition.KeyCondition != null)
{
if (condition.KeyCondition.Invoke(key))
{
foreach (string word in _chains.GetValues(key))
{
if (condition.WordCondition != null)
{
if (condition.WordCondition.Invoke(word))
{
newMap.AddToChain(key, word);
valuesFound = true;
}
}
}
}
}
}
if (!valuesFound)
{
throw new Exceptions.NoPossibleElements("Chain map filter filtered everything out");
}
return(newMap);
}
/// <summary>
/// Compare chain tables ignoring duplicates
/// </summary>
public static void CompareChainTablesNoDuplicates(ChainMap inputChainMap1,
ChainMap inputChainMap2)
{
CompareChainTables(GetUnderlyingDictionary(inputChainMap1),
GetUnderlyingDictionary(inputChainMap2), true);
}
public static void CompareChainTables(ChainMap inputChainMap,
Dictionary<ChainKey, List<string>> inputChains)
{
CompareChainTables(GetUnderlyingDictionary(inputChainMap), inputChains) ;
}
public void T_GetSubChain()
{
WordGenerator gen = InitSimpleWordGen() ;
//Should give me both "hello world one" and "hello world two"
ChainMap tempMap = gen.GetSubChain(new ChainCondition(cw => cw.Words[0] == "hello", w => w.Length == 3)) ;
ChainMap correctMap = new ChainMap() ;
correctMap.AddToChain(new ChainKey(new string[] {"hello", "world"}), "one") ;
correctMap.AddToChain(new ChainKey(new string[] {"hello", "world"}), "two") ;
TestUtils.CompareChainTables(correctMap, tempMap) ;
//Should give me just "hello world one"
tempMap = gen.GetSubChain(new ChainCondition(cw => cw.Words[0] == "hello", w => w.StartsWith("o"))) ;
correctMap = new ChainMap() ;
correctMap.AddToChain(new ChainKey(new string[] {"hello", "world"}), "one") ;
TestUtils.CompareChainTables(correctMap, tempMap) ;
//If passed in condition is null nothing should change
tempMap = gen.GetSubChain(new ChainCondition(null, null)) ;
TestUtils.CompareChainTables(gen.Chains, tempMap) ;
//If impossible condition is passed in exception should be thrown
Assert.Throws(typeof(Exceptions.NoPossibleElements), delegate
{ gen.GetSubChain(new ChainCondition(null, w => w == "Does not exist")) ;}) ;
}
public void T_GetRandomKey_WithParams()
{
WordGenerator gen = InitSimpleWordGen() ;
ChainMap subMap = new ChainMap() ;
ChainKey key1 = new ChainKey(new string[]{"key1", "key2", "key3"}) ;
ChainKey key2 = new ChainKey(new string[]{"key1", "key2", "key4"}) ;
subMap.AddToChain(key1, "val1") ;
subMap.AddToChain(key2, "val2") ;
bool key1Found, key2Found ;
key1Found = key2Found = false ;
for(int i = 0 ; i < 10 ; i++)
{
ChainKey currKey = gen.GetRandomKey(subMap);
if(key1.Equals(currKey))
{
key1Found = true ;
}
else if(key2.Equals(currKey))
{
key2Found = true ;
}
else
{
Assert.Fail("Invalid key returned") ;
}
}
if(!(key1Found && key2Found))
{
Assert.Fail("GetRandomKey is not random") ;
}
}
/// <summary>
/// Get a random key from passed in chain map
/// The probability of getting a key should be proportional to the number of values
/// </summary>
/// <returns></returns>
internal ChainKey GetRandomKey(ChainMap map)
{
ChainKey[] keys = CreateKeysArray(map, _alwaysTrueCondition.KeyCondition) ;
return keys[_rand.Next(keys.Length)];
}
/// <summary>
/// Initializes word generator with default random seed
/// </summary>
/// <param name="chains"></param>
public WordGenerator(ChainMap chains) : this(chains, null)
{
}
/// <summary>
/// Reset CurrentWord based on conditions
/// </summary>
/// <param name="keyCondition"> Condition for key of first word </param>
/// <param name="onEndCondition"> Condition for new word after there are no more chains
/// By default this is the same as @keyCondition </param>
private void Reset(ChainCondition initialCondition, ChainCondition onEndCondition)
{
ChainCondition realInitialConditions = initialCondition;
//Set null conditions to always true conditions to simplify our code
if(realInitialConditions == null)
{
realInitialConditions = _alwaysTrueCondition;
}
else
{
if (realInitialConditions.KeyCondition == null)
{
realInitialConditions.KeyCondition = _alwaysTrueCondition.KeyCondition;
}
if (realInitialConditions.WordCondition == null)
{
realInitialConditions.WordCondition = _alwaysTrueCondition.WordCondition;
}
}
ChainCondition realOnEndCondition = onEndCondition ;
//Set on end condition to start condition if it is null
if(realOnEndCondition == null)
{
realOnEndCondition = realInitialConditions ;
}
else
{
if (realOnEndCondition.KeyCondition == null)
{
realOnEndCondition.KeyCondition = _alwaysTrueCondition.KeyCondition;
}
if (realOnEndCondition.WordCondition == null)
{
realOnEndCondition.WordCondition = _alwaysTrueCondition.WordCondition;
}
}
ChainMap initialConditionMap ;
//Only generate subchains if we need to
if(realInitialConditions != _alwaysTrueCondition)
{
initialConditionMap = GetSubChain(realInitialConditions) ;
}
else
{
initialConditionMap = Chains;
}
ChainKey[] initialConditionSubKeys = CreateKeysArray(initialConditionMap,
_alwaysTrueCondition.KeyCondition) ;
//All chains and words should match condition so we can just get random
ChainKey currKey = GetRandomKey(initialConditionSubKeys) ;
string currWord ;
GetCandidate(initialConditionMap.GetValues(currKey), null, out currWord) ;
if(realOnEndCondition != _alwaysTrueCondition)
{
//Verify on end map has valid elements. If no exception is thrown we are good to go
_onEndSubChains = GetSubChain(realOnEndCondition) ;
}
else
{
_onEndSubChains = initialConditionMap;
}
CurrentWord = currWord;
_currKey = currKey;
_initialConditionSubChains = initialConditionMap ;
_initialConditionSubKeys = initialConditionSubKeys;
_currentOnEndCondition = realOnEndCondition;
SubchainsInitialized = true ;
}
/// <summary>
/// Get a random key from passed in chain map
/// The probability of getting a key should be proportional to the number of values
/// </summary>
/// <returns></returns>
internal ChainKey GetRandomKey(ChainMap map)
{
ChainKey[] keys = CreateKeysArray(map, _alwaysTrueCondition.KeyCondition);
return(keys[_rand.Next(keys.Length)]);
}
/// <summary>
/// Get random key from passed in chain map matching passed in condition
/// </summary>
/// <param name="map"></param>
/// <param name="keyCondition"></param>
/// <returns></returns>
internal ChainKey GetRandomKey(ChainMap map, Predicate<ChainKey> keyCondition)
{
ChainKey[] keys = CreateKeysArray(map, keyCondition) ;
return keys[_rand.Next(keys.Length)];
}
/// <summary>
/// Reset CurrentWord based on conditions
/// </summary>
/// <param name="keyCondition"> Condition for key of first word </param>
/// <param name="onEndCondition"> Condition for new word after there are no more chains
/// By default this is the same as @keyCondition </param>
private void Reset(ChainCondition initialCondition, ChainCondition onEndCondition)
{
ChainCondition realInitialConditions = initialCondition;
//Set null conditions to always true conditions to simplify our code
if (realInitialConditions == null)
{
realInitialConditions = _alwaysTrueCondition;
}
else
{
if (realInitialConditions.KeyCondition == null)
{
realInitialConditions.KeyCondition = _alwaysTrueCondition.KeyCondition;
}
if (realInitialConditions.WordCondition == null)
{
realInitialConditions.WordCondition = _alwaysTrueCondition.WordCondition;
}
}
ChainCondition realOnEndCondition = onEndCondition;
//Set on end condition to start condition if it is null
if (realOnEndCondition == null)
{
realOnEndCondition = realInitialConditions;
}
else
{
if (realOnEndCondition.KeyCondition == null)
{
realOnEndCondition.KeyCondition = _alwaysTrueCondition.KeyCondition;
}
if (realOnEndCondition.WordCondition == null)
{
realOnEndCondition.WordCondition = _alwaysTrueCondition.WordCondition;
}
}
ChainMap initialConditionMap;
//Only generate subchains if we need to
if (realInitialConditions != _alwaysTrueCondition)
{
initialConditionMap = GetSubChain(realInitialConditions);
}
else
{
initialConditionMap = Chains;
}
ChainKey[] initialConditionSubKeys = CreateKeysArray(initialConditionMap,
_alwaysTrueCondition.KeyCondition);
//All chains and words should match condition so we can just get random
ChainKey currKey = GetRandomKey(initialConditionSubKeys);
string currWord;
GetCandidate(initialConditionMap.GetValues(currKey), null, out currWord);
if (realOnEndCondition != _alwaysTrueCondition)
{
//Verify on end map has valid elements. If no exception is thrown we are good to go
_onEndSubChains = GetSubChain(realOnEndCondition);
}
else
{
_onEndSubChains = initialConditionMap;
}
CurrentWord = currWord;
_currKey = currKey;
_initialConditionSubChains = initialConditionMap;
_initialConditionSubKeys = initialConditionSubKeys;
_currentOnEndCondition = realOnEndCondition;
SubchainsInitialized = true;
}
/// <summary>
/// Get subchain of chainkeys and words that satisfies the passed in condition
/// </summary>
/// <param name="condition"></param>
/// <returns></returns>
internal ChainMap GetSubChain(ChainCondition condition)
{
//If conditions won't be applied return original chains
if(condition == null || condition == _alwaysTrueCondition ||
(condition.WordCondition == null && condition.KeyCondition == null))
{
return _chains ;
}
ChainMap newMap = new ChainMap() ;
bool valuesFound = false ;
foreach(ChainKey key in _chains.GetAllKeys())
{
if(condition.KeyCondition != null)
{
if(condition.KeyCondition.Invoke(key))
{
foreach(string word in _chains.GetValues(key))
{
if(condition.WordCondition != null)
{
if(condition.WordCondition.Invoke(word))
{
newMap.AddToChain(key, word) ;
valuesFound = true ;
}
}
}
}
}
}
if(!valuesFound)
{
throw new Exceptions.NoPossibleElements("Chain map filter filtered everything out") ;
}
return newMap ;
}
/// <summary>
/// Initializes word generator with default random seed
/// </summary>
/// <param name="chains"></param>
public WordGenerator(ChainMap chains)
: this(chains, null)
{
}
public static Dictionary<ChainKey, List<string>> GetUnderlyingDictionary(ChainMap inputChainMap)
{
Dictionary<ChainKey, List<string>> retValues = new Dictionary<ChainKey, List<string>>() ;
List<ChainKey> keys = inputChainMap.GetAllKeys() ;
foreach(ChainKey key in keys)
{
retValues.Add(key, inputChainMap.GetValues(key)) ;
}
return retValues;
}
/// <summary>
/// Get random key from passed in chain map matching passed in condition
/// </summary>
/// <param name="map"></param>
/// <param name="keyCondition"></param>
/// <returns></returns>
internal ChainKey GetRandomKey(ChainMap map, Predicate <ChainKey> keyCondition)
{
ChainKey[] keys = CreateKeysArray(map, keyCondition);
return(keys[_rand.Next(keys.Length)]);
}
private ChainKey[] CreateKeysArray(ChainMap map, Predicate<ChainKey> keyCondition)
{
List<ChainKey> newKeys = new List<ChainKey>() ;
List<ChainKey> origKeys = map.GetAllKeys() ;
foreach(ChainKey origKey in origKeys)
{
if(keyCondition.Invoke(origKey))
{
//Add key multiple times to ensure probability of picking it is proportional to the
//number of values
foreach(string val in map.GetValues(origKey))
{
newKeys.Add(origKey) ;
}
}
}
return newKeys.ToArray() ;
}
