private void CreateTADetector()
{
lock (this)
{
if (taDetector == null)
{
taDetector = new TagAffixDetector(flags);
}
}
}
public virtual ICollection <string> FeaturesCpC(PaddedList <IN> cInfo, int loc)
{
ICollection <string> features = new List <string>();
CoreLabel c = cInfo[loc];
CoreLabel c1 = cInfo[loc + 1];
CoreLabel c2 = cInfo[loc + 2];
CoreLabel c3 = cInfo[loc + 3];
CoreLabel p = cInfo[loc - 1];
CoreLabel p2 = cInfo[loc - 2];
CoreLabel p3 = cInfo[loc - 3];
string charc = c.Get(typeof(CoreAnnotations.CharAnnotation));
if (charc == null)
{
charc = string.Empty;
}
string charc1 = c1.Get(typeof(CoreAnnotations.CharAnnotation));
if (charc1 == null)
{
charc1 = string.Empty;
}
string charc2 = c2.Get(typeof(CoreAnnotations.CharAnnotation));
if (charc2 == null)
{
charc2 = string.Empty;
}
string charc3 = c3.Get(typeof(CoreAnnotations.CharAnnotation));
if (charc3 == null)
{
charc3 = string.Empty;
}
string charp = p.Get(typeof(CoreAnnotations.CharAnnotation));
if (charp == null)
{
charp = string.Empty;
}
string charp2 = p2.Get(typeof(CoreAnnotations.CharAnnotation));
if (charp2 == null)
{
charp2 = string.Empty;
}
string charp3 = p3.Get(typeof(CoreAnnotations.CharAnnotation));
if (charp3 == null)
{
charp3 = string.Empty;
}
/*
* N-gram features. N is upto 2.
*/
if (flags.useWord2)
{
// features.add(charc +"c");
// features.add(charc1+"c1");
// features.add(charp +"p");
// features.add(charp +charc +"pc");
// if( flags.useMsr ){
// features.add(charc +charc1 +"cc1");
// features.add(charp + charc1 +"pc1");
// }
features.Add(charc + "::c");
features.Add(charc1 + "::c1");
features.Add(charp + "::p");
features.Add(charp2 + "::p2");
// trying to restore the features that Huishin described in SIGHAN 2005 paper
features.Add(charc + charc1 + "::cn");
features.Add(charp + charc + "::pc");
features.Add(charp + charc1 + "::pn");
features.Add(charp2 + charp + "::p2p");
features.Add(charp2 + charc + "::p2c");
features.Add(charc2 + charc + "::n2c");
features.Add("|word2");
}
/*
* Radical N-gram features. N is upto 4.
* Smoothing method of N-gram, because there are too many characters in Chinese.
* (It works better than N-gram when they are used individually. less sparse)
*/
char rcharc;
char rcharc1;
char rcharc2;
char rcharc3;
char rcharp;
char rcharp1;
char rcharp2;
char rcharp3;
if (charc.Length == 0)
{
rcharc = 'n';
}
else
{
rcharc = RadicalMap.GetRadical(charc[0]);
}
if (charc1.Length == 0)
{
rcharc1 = 'n';
}
else
{
rcharc1 = RadicalMap.GetRadical(charc1[0]);
}
if (charc2.Length == 0)
{
rcharc2 = 'n';
}
else
{
rcharc2 = RadicalMap.GetRadical(charc2[0]);
}
if (charc3.Length == 0)
{
rcharc3 = 'n';
}
else
{
rcharc3 = RadicalMap.GetRadical(charc3[0]);
}
if (charp.Length == 0)
{
rcharp = 'n';
}
else
{
rcharp = RadicalMap.GetRadical(charp[0]);
}
if (charp2.Length == 0)
{
rcharp2 = 'n';
}
else
{
rcharp2 = RadicalMap.GetRadical(charp2[0]);
}
if (charp3.Length == 0)
{
rcharp3 = 'n';
}
else
{
rcharp3 = RadicalMap.GetRadical(charp3[0]);
}
if (flags.useRad2)
{
features.Add(rcharc + "rc");
features.Add(rcharc1 + "rc1");
features.Add(rcharp + "rp");
features.Add(rcharp + rcharc + "rpc");
features.Add(rcharc + rcharc1 + "rcc1");
features.Add(rcharp + rcharc + rcharc1 + "rpcc1");
features.Add("|rad2");
}
/* non-word dictionary:SEEM bi-gram marked as non-word */
if (flags.useDict2)
{
NonDict2 nd = new NonDict2(flags);
features.Add(nd.CheckDic(charp + charc, flags) + "nondict");
features.Add("|useDict2");
}
if (flags.useOutDict2)
{
if (outDict == null)
{
logger.Info("reading " + flags.outDict2 + " as a seen lexicon");
outDict = new CorpusDictionary(flags.outDict2, true);
}
features.Add(outDict.GetW(charp + charc) + "outdict");
// -1 0
features.Add(outDict.GetW(charc + charc1) + "outdict");
// 0 1
features.Add(outDict.GetW(charp2 + charp) + "outdict");
// -2 -1
features.Add(outDict.GetW(charp2 + charp + charc) + "outdict");
// -2 -1 0
features.Add(outDict.GetW(charp3 + charp2 + charp) + "outdict");
// -3 -2 -1
features.Add(outDict.GetW(charp + charc + charc1) + "outdict");
// -1 0 1
features.Add(outDict.GetW(charc + charc1 + charc2) + "outdict");
// 0 1 2
features.Add(outDict.GetW(charp + charc + charc1 + charc2) + "outdict");
}
// -1 0 1 2
/*
* (CTB/ASBC/HK/PK/MSR) POS information of each characters.
* If a character falls into some function categories,
* it is very likely there is a boundary.
* A lot of Chinese function words belong to single characters.
* This feature is also good for numbers and punctuations.
* DE* are grouped into DE.
*/
if (flags.useCTBChar2 || flags.useASBCChar2 || flags.useHKChar2 || flags.usePKChar2 || flags.useMSRChar2)
{
string[] tagsets;
// the "useChPos" now only works for CTB and PK
if (flags.useChPos)
{
if (flags.useCTBChar2)
{
tagsets = new string[] { "AD", "AS", "BA", "CC", "CD", "CS", "DE", "DT", "ETC", "IJ", "JJ", "LB", "LC", "M", "NN", "NR", "NT", "OD", "P", "PN", "PU", "SB", "SP", "VA", "VC", "VE", "VV" };
}
else
{
if (flags.usePKChar2)
{
//tagsets = new String[]{"r", "j", "t", "a", "nz", "l", "vn", "i", "m", "ns", "nr", "v", "n", "q", "Ng", "b", "d", "nt"};
tagsets = new string[] { "2", "3", "4" };
}
else
{
throw new Exception("only support settings for CTB and PK now.");
}
}
}
else
{
//logger.info("Using Derived features");
tagsets = new string[] { "2", "3", "4" };
}
if (taDetector == null)
{
taDetector = new TagAffixDetector(flags);
}
foreach (string tagset in tagsets)
{
features.Add(taDetector.CheckDic(tagset + "p", charp) + taDetector.CheckDic(tagset + "i", charp) + taDetector.CheckDic(tagset + "s", charc) + taDetector.CheckInDic(charp) + taDetector.CheckInDic(charc) + tagset + "prep-sufc");
}
}
// features.add("|ctbchar2"); // Added a constant feature several times!!
/*
* In error analysis, we found English words and numbers are often separated.
* Rule 1: isNumber feature: check if the current and previous char is a number.
* Rule 2: Disambiguation of time point and time duration.
* Rule 3: isEnglish feature: check if the current and previous character is an english letter.
* Rule 4: English name feature: check if the current char is a conjunct pu for English first and last name, since there is no space between two names.
* Most of PUs are a good indicator for word boundary, but - and . is a strong indicator that there is no boundry within a previous , a follow char and it.
*/
if (flags.useRule2)
{
/* Reduplication features */
// previous character == current character
if (charp.Equals(charc))
{
features.Add("11");
}
// previous character == next character
if (charp.Equals(charc1))
{
features.Add("22");
}
// current character == next next character
// fire only when usePk and useHk are both false.
// Notice: this should be (almost) the same as the "22" feature, but we keep it for now.
if (!flags.usePk && !flags.useHk)
{
if (charc.Equals(charc2))
{
features.Add("33");
}
}
char cur1 = ' ';
char cur2 = ' ';
char cur = ' ';
char pre = ' ';
// actually their length must be either 0 or 1
if (charc1.Length > 0)
{
cur1 = charc1[0];
}
if (charc2.Length > 0)
{
cur2 = charc2[0];
}
if (charc.Length > 0)
{
cur = charc[0];
}
if (charp.Length > 0)
{
pre = charp[0];
}
string prer = rcharp.ToString();
// the radical of previous character
Pattern E = Pattern.Compile("[a-zA-Z]");
Pattern N = Pattern.Compile("[0-9]");
Matcher m = E.Matcher(charp);
Matcher ce = E.Matcher(charc);
Matcher pe = E.Matcher(charp2);
Matcher cn = N.Matcher(charc);
Matcher pn = N.Matcher(charp2);
// if current and previous characters are numbers...
if (cur >= '0' && cur <= '9' && pre >= '0' && pre <= '9')
{
if (cur == '9' && pre == '1' && cur1 == '9' && cur2 >= '0' && cur2 <= '9')
{
//199x
features.Add("YR");
}
else
{
features.Add("2N");
}
}
else
{
// if current and previous characters are not both numbers
// but previous char is a number
// i.e. patterns like "1N" , "2A", etc
if (pre >= '0' && pre <= '9')
{
features.Add("1N");
}
else
{
// if previous character is an English character
if (m.Matches())
{
features.Add("E");
}
else
{
// if the previous character contains no radical (and it exist)
if (prer.Equals(".") && charp.Length == 1)
{
// fire only when usePk and useHk are both false. Not sure why. -pichuan
if (!flags.useHk && !flags.usePk)
{
if (ce.Matches())
{
features.Add("PU+E");
}
if (pe.Matches())
{
features.Add("E+PU");
}
if (cn.Matches())
{
features.Add("PU+N");
}
if (pn.Matches())
{
features.Add("N+PU");
}
}
features.Add("PU");
}
}
}
}
string engType = IsEnglish(charp, charc);
string engPU = IsEngPU(charp);
if (!engType.Equals(string.Empty))
{
features.Add(engType);
}
if (!engPU.Equals(string.Empty) && !engType.Equals(string.Empty))
{
features.Add(engPU + engType);
}
}
//end of use rule
// features using "Character.getType" information!
string origS = c.Get(typeof(CoreAnnotations.OriginalCharAnnotation));
char origC = ' ';
if (origS.Length > 0)
{
origC = origS[0];
}
int type = char.GetType(origC);
switch (type)
{
case char.UppercaseLetter:
case char.LowercaseLetter:
{
// A-Z and full-width A-Z
// a-z and full-width a-z
features.Add("CHARTYPE-LETTER");
break;
}
case char.DecimalDigitNumber:
{
features.Add("CHARTYPE-DECIMAL_DIGIT_NUMBER");
break;
}
case char.OtherLetter:
{
// mostly chinese chars
features.Add("CHARTYPE-OTHER_LETTER");
break;
}
default:
{
// other types
features.Add("CHARTYPE-MISC");
break;
}
}
return(features);
}
