src/main/java/weka/core/stemmers/PTStemmer.java
public String stem(String word) {
	String ret = null;
    try {
	  ret = getActualStemmer().getWordStem(word);
	}
    catch (PTStemmerException e) {
      e.printStackTrace();
	}
    return ret;
  }
public String stem(String word) {
	String ret = null;
    try {
	  ret = getActualStemmer().getWordStem(word);
	}
    catch (PTStemmerException e) {
      e.printStackTrace();
	}
    return ret;
  }
Returns the stemmed version of the given word.
Word is converted to lower case before stemming.

@param word 	a string consisting of a single word
@return 		the stemmed word