package apr;
import java.io.BufferedWriter;import java.io.FileWriter;import java.util.*;
public class Apriori {
private double minsup = 0.6;// 最小支持度 private double minconf = 0.2;// 最小置信度
// 注意使用IdentityHashMap，否则由于关联规则产生存在键值相同的会出现覆盖 private IdentityHashMap ruleMap = new IdentityHashMap();
private String[] transSet = { "abc", "abc", "acde", "bcdf", "abcd", "abcdf" };// 事务集合，可以根据需要从构造函数里传入
private int itemCounts = 0;// 候选1项目集大小,即字母的个数 private TreeSet[] frequencySet = new TreeSet[40];// 频繁项集数组，[0]:代表1频繁集... private TreeSet maxFrequency = new TreeSet();// 最大频繁集 private TreeSet candidate = new TreeSet();// 1候选集 private TreeSet candidateSet[] = new TreeSet[40];// 候选集数组 private int frequencyIndex;
public Apriori() {
maxFrequency = new TreeSet(); itemCounts = counts();// 初始化1候选集的大小
// 初始化其他两个 for (int i = 0; i < itemCounts; i++) { frequencySet[i] = new TreeSet(); candidateSet[i] = new TreeSet(); } candidateSet[0] = candidate; }
public Apriori(String[] transSet) { this.transSet = transSet; maxFrequency = new TreeSet(); itemCounts = counts();// 初始化1候选集的大小
// 初始化其他两个 for (int i = 0; i < itemCounts; i++) { frequencySet[i] = new TreeSet(); candidateSet[i] = new TreeSet(); } candidateSet[0] = candidate; }
public int counts() {
String temp1 = null; char temp2 = 'a'; // 遍历所有事务集String 加入集合，set自动去重了 for (int i = 0; i < transSet.length; i++) { temp1 = transSet[i]; for (int j = 0; j < temp1.length(); j++) { temp2 = temp1.charAt(j); candidate.add(String.valueOf(temp2)); } } return candidate.size(); }
public void item1_gen() { String temp1 = ""; double m = 0;
Iterator temp = candidateSet[0].iterator(); while (temp.hasNext()) { temp1 = (String) temp.next(); m = count_sup(temp1);
// 符合条件的加入 1候选集 if (m >= minsup * transSet.length) { frequencySet[0].add(temp1); } } }
public double count_sup(String x) { int temp = 0; for (int i = 0; i < transSet.length; i++) { for (int j = 0; j < x.length(); j++) { if (transSet[i].indexOf(x.charAt(j)) == -1) break; else if (j == (x.length() - 1)) temp++; } } return temp; }
public void canditate_gen(int k) { String y = "", z = "", m = ""; char c1 = 'a', c2 = 'a';
Iterator temp1 = frequencySet[k - 2].iterator(); Iterator temp2 = frequencySet[0].iterator(); TreeSet h = new TreeSet();
while (temp1.hasNext()) { y = (String) temp1.next(); c1 = y.charAt(y.length() - 1);
while (temp2.hasNext()) { z = (String) temp2.next();
c2 = z.charAt(0); if (c1 >= c2) continue; else { m = y + z; h.add(m); } } temp2 = frequencySet[0].iterator(); } candidateSet[k - 1] = h; }
// k候选集=>k频繁集 public void frequent_gen(int k) { String s1 = "";
Iterator ix = candidateSet[k - 1].iterator(); while (ix.hasNext()) { s1 = (String) ix.next(); if (count_sup(s1) >= (minsup * transSet.length)) { frequencySet[k - 1].add(s1); } } }
public boolean is_frequent_empty(int k) { if (frequencySet[k - 1].isEmpty()) return true; else return false; }
public boolean included(String s1, String s2) { for (int i = 0; i < s1.length(); i++) { if (s2.indexOf(s1.charAt(i)) == -1) return false; else if (i == s1.length() - 1) return true; } return true; }
public void maxfrequent_gen() { int i, j; Iterator iterator, iterator1, iterator2; String temp = "", temp1 = "", temp2 = ""; for (i = 1; i < frequencyIndex; i++) { maxFrequency.addAll(frequencySet[i]); } // for (i = 0; i < frequencyIndex; i++) { // iterator1 = frequencySet[i].iterator(); // while (iterator1.hasNext()) { // temp1 = (String) iterator1.next(); // for (j = i + 1; j < frequencyIndex; j++) { // iterator2 = frequencySet[j].iterator(); // while (iterator2.hasNext()) { // temp2 = (String) iterator2.next(); // if (included(temp1, temp2)) // maxFrequency.remove(temp1); // } // } // } // } }
public void print_maxfrequent() { Iterator iterator = maxFrequency.iterator(); System.out.print("产生规则频繁项集："); while (iterator.hasNext()) { System.out.print(toDigit((String) iterator.next()) + "/t"); } System.out.println(); }
public void rulePrint() { String x, y; double temp = 0;
Set hs = ruleMap.keySet(); Iterator iterator = hs.iterator();
StringBuffer sb = new StringBuffer(); System.out.println("关联规则："); while (iterator.hasNext()) { x = (String) iterator.next();
y = (String) ruleMap.get(x);
temp = (count_sup(x + y) / count_sup(x)); //x = toDigit(x); //y = toDigit(y);
System.out.println(x + (x.length() < 5 ? "/t" : "") + "-->" + y + "/t" + temp); sb.append(" " + x + (x.length() < 5 ? "/t" : "") + "-->" + y + "/t" + temp + "/t/n"); } BufferedWriter bw = null; try { FileWriter fw = new FileWriter("Asr.txt");
bw = new BufferedWriter(fw);
bw.write("最小支持度 minsup = " + minsup); bw.newLine(); bw.write("最小置信度 minconf = " + minconf); bw.newLine(); bw.write("产生关联规则如下: "); bw.newLine();
bw.write(sb.toString()); // bw.newLine();
if (bw != null) bw.close(); } catch (Exception e) { e.printStackTrace(); }
}
public void subGen(String s) { String x = "", y = ""; for (int i = 1; i < (1 << s.length()) - 1; i++) { for (int j = 0; j < s.length(); j++) { if (((1 << j) & i) != 0) { x += s.charAt(j); } }
for (int j = 0; j < s.length(); j++) { if (((1 << j) & (~i)) != 0) {
y += s.charAt(j);
} } if (count_sup(x + y) / count_sup(x) >= minconf) { ruleMap.put(x, y); } x = ""; y = "";
} }
public void ruleGen() { String s; Iterator iterator = maxFrequency.iterator(); while (iterator.hasNext()) { s = (String) iterator.next(); subGen(s); } }
// for test public void print1() { Iterator temp = candidateSet[0].iterator(); while (temp.hasNext()) System.out.println(temp.next()); }
// for test public void print2() { Iterator temp = frequencySet[0].iterator(); while (temp.hasNext()) System.out.println((String) temp.next()); }
// for test public void print3() { canditate_gen(1); frequent_gen(2); Iterator temp = candidateSet[1].iterator(); Iterator temp1 = frequencySet[1].iterator(); while (temp.hasNext()) System.out.println("候选" + (String) temp.next()); while (temp1.hasNext()) System.out.println("频繁" + (String) temp1.next()); }
public void print_canditate() {
for (int i = 0; i < frequencySet[0].size(); i++) { Iterator ix = candidateSet[i].iterator(); Iterator iy = frequencySet[i].iterator(); System.out.print("候选集" + (i + 1) + ":"); while (ix.hasNext()) { System.out.print((String) ix.next() + "/t"); //System.out.print(toDigit((String) ix.next()) + "/t"); } System.out.print("/n" + "频繁集" + (i + 1) + ":"); while (iy.hasNext()) { System.out.print((String) iy.next() + "/t"); //System.out.print(toDigit((String) iy.next()) + "/t"); } System.out.println(); } }
private String toDigit(String str) { if (str != null) { StringBuffer temp = new StringBuffer();
for (int i = 0; i < str.length(); i++) { char c = str.charAt(i); temp.append(((int) c - 65) + " "); }
return temp.toString(); } else { return null; }
}
public String[] getTrans_set() { return transSet; }
public void setTrans_set(String[] transSet) { transSet = transSet; }
public double getMinsup() { return minsup; }
public void setMinsup(double minsup) { this.minsup = minsup; }
public double getMinconf() { return minconf; }
public void setMinconf(double minconf) { this.minconf = minconf; }
public void run() { int k = 1;
item1_gen();
do { k++; canditate_gen(k); frequent_gen(k); } while (!is_frequent_empty(k)); frequencyIndex = k - 1; print_canditate(); maxfrequent_gen(); print_maxfrequent(); ruleGen(); rulePrint();
} public static void main(String[] args) { Apriori ap = new Apriori(); ap.run(); }
}
