“Introduction to Programming With Java”

“Introduction to Programming With Java” Lecture - 11 UMESHPATIL (umesh@cse.iitb.ac.in) nlp-ai@cse.iitb

Contents for Today’s Lecture • Programming practice: Program for morphological analysis of English nouns. nlp-ai@cse.iitb

Problem Write a Java program that finds out the root & suffix of the given noun plural in English. Also print the morphology rule applied for forming the plural. Sample input & output –Input:boysOutput: root = boy suffix = s Morphology rule = [[W]]  [[W][s]] Input:indicesOutput: root = index suffix = ices Morphology rule = [[W][ex]]  [[W][ices]] nlp-ai@cse.iitb

Plurals in English • Example • boy  boys • bus  buses • lady ladies • leaf leaves • datum data • formula  formulae • index indices • matrix matrices • radius radii • cherub  cherubim • Morphology Rule • W  Ws • W  Wes • Wy Wies • Wf Wves • Wum Wa • W  We • Wex Wices • Wx Wces • Wus Wi • W  Wim nlp-ai@cse.iitb

Algorithm • Read the input word • Find the suffix • Remove suffix & get the root • If needed, prepare the correct rooteg. indices  ind  ind + ex = index • Print the output nlp-ai@cse.iitb

Required Methods of String class • boolean endsWith(Stringsuffix)Returns true if the string ends with the specified suffix; false otherwise. Parameters: the String suffix. • eg. If s = “indices” thens.endsWith(“ices”) will return trues.endsWith(“s”) will return trues.endsWith(“”) will return trues.endsWith(“indices”) will return trueButs.endsWith(“ice”) will return false nlp-ai@cse.iitb

Required Methods of String class… continued • String substring(intbeginIndex, intendIndex)Returns a new string that is a substring of the current string. The substring begins at the specified beginIndex and extends to the character at index endIndex - 1. It will give error (throw exception) if the beginIndex is negative, or endIndex is larger than the length the string, or beginIndex is larger than endIndex.Parameters:beginIndex - the beginning index, inclusive.endIndex - the ending index, exclusive. • eg. If s = “mississippi” thens.substring(0,4) will return “miss”s.substring(6,9) will return “sip”s.substring(0,11) will return “mississippi”s.substring(0,0) will return “” nlp-ai@cse.iitb

Required Methods of String class… continued • int lastIndexOf(Stringstr)Returns the index within the current string of the rightmost occurrence of the specified substring. If str does not occur as a substring, -1 is returned.Parameters: str - the substring to search for. • eg. If s = “mississippi” thens.lastIndexOf(“is”) will return 4s.lastIndexOf(“i”) will return 10s.lastIndexOf(“”) will return 11s.lastIndexOf(“mississippi”) will return 0Ands.lastIndexOf(“abc”) will return -1 nlp-ai@cse.iitb

Required Methods of String class… continued • String concat(Stringstr)Returns a string after concatenating the specified string, ie. str, to the end of the current string.Parameters:str - the string that is concatenated to the end of the current string. • eg. if s = “man” thens.concat(“go”) will return “mango”s.concat(“”) will return “man” • Detailed explanation of the String class. nlp-ai@cse.iitb

Core Part of the Program • Suppose input word = “indices”; • if (word.endsWith("ices")) { // word = “indices” • suffix = "ices"; • i = word.lastIndexOf("ices"); // i = 3 • root = word.substring(0,i); // root = “ind” • root = root.concat("ex"); // root = “index” • morphRule = "[[W][ex]]  [[W][ices]]"; • } nlp-ai@cse.iitb

Some Testing • matrix  matrices • life  lives • analysis  analyses • criterion  criteria • Does the program work for these examples? • If yes, how? • If no, why? nlp-ai@cse.iitb

Assignment • Do the morphological analysis of the following inflected verbs in English and write a Java program that finds out the root & suffix of the given inflected verb. Also print the morphology rule that is applied. • fetch  fetches, fetching, fetched • carry  carries, carrying, carried • enjoy  enjoys, enjoying, enjoyed • burn  burns, burning, burnt • beat  beats, beating, beaten • forbid  forbids, forbidding, forbided, forbidden • blow  blows, blowing, blowed, blown • save  saves, saving, saved nlp-ai@cse.iitb

Assignment … continued say  says, saying, said drop  drops, dropping, dropped admit  admits, admitting, admitted repel  repels, repelling, repelled dog  dogs, dogging, dogged can  cans, canning, canned spur  spurs, spurring, spurred stem  stems, stemming, stemmed stab  stabs, stabbing, stabbed kid  kids, kidding, kidded mimic  mimics, mimicking, mimicked nlp-ai@cse.iitb

To Remind The best way to learn programming is writing a lot of programs on your own. nlp-ai@cse.iitb

End Thank you  nlp-ai@cse.iitb

“Introduction to Programming With Java”