form1.cs

c#实现的APRIORI算法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Collections;

namespace Apriori
{
    //事务
    struct trans
    {
        public string tID;
        public ArrayList items;
    }

    //项集和支持度计数
    struct itemAndSup
    {
        public ArrayList items;
        public int sup;
    }

    public partial class Form1 : Form
    {
        private ArrayList tData = new ArrayList();      //事务数据
        private int minSup = 2;                             //最小支持度计数阀值
        private ArrayList C0 = new ArrayList();         //L的超集
        private ArrayList L0 = new ArrayList();         //频繁k项集
        private int step;                               //已完成步骤数
        private bool finish;                            //算法是否完成

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Reset();
            //test1();
        }

        private void Reset()
        {
            tData.Clear();
            C0.Clear();
            L0.Clear();
            this.TDataView.Items.Clear();
            this.CResultView.Items.Clear();
            this.LResultView.Items.Clear();
            this.TDataView.Items.Add("TID\t商品ID的列表\n");
            this.MinSupTextBox.Text = minSup.ToString();
            step = 0;
            finish = false;
        }

        private void AddItem_Click(object sender, EventArgs e)
        {
            Trans addTrans = new Trans();
            if (addTrans.ShowDialog() == DialogResult.OK)
            {
                trans t = new trans();
                t.tID = addTrans.GetTID();
                t.items = addTrans.GetItemList();
                AddItemToDataView(t);
                tData.Add(t);
            }
        }

        private void DeleteItem_Click(object sender, EventArgs e)
        {
            if (this.TDataView.SelectedIndex == 0)
                return;
            tData.RemoveAt(this.TDataView.SelectedIndex - 1);
            this.TDataView.Items.RemoveAt(this.TDataView.SelectedIndex);         
        }

        private void Next_Click(object sender, EventArgs e)
        {
            if (finish == true)
            {
                this.Next.Text = "计算下一步";
                Reset();
                return;
            }

            ArrayList OldL = new ArrayList(L0);
            //增加步骤计数，用来决定计算Ｃ或者是Ｌ。
            step++;

            //计算L
            if (step % 2 == 1)
            {
                //找出频繁1项集L1
                if (step == 1)
                {
                    for (int i = 0; i < tData.Count; i++)
                    {
                        trans t = (trans)tData[i];
                        for (int j = 0; j < t.items.Count; j++)
                        {
                            bool flag = true;
                            for (int k = 0; k < L0.Count; k++)
                            {
                                if (((itemAndSup)L0[k]).items[0] == t.items[j])
                                {
                                    flag = false;
                                    break;
                                }
                            }
                            if (flag == false)
                                continue;

                            ArrayList items = new ArrayList();
                            items.Add(t.items[j]);
                            int sup = FindItemSup(items);
                            if (sup >= minSup)
                            {
                                itemAndSup temp = new itemAndSup();
                                temp.sup = sup;
                                temp.items = items;
                                L0.Add(temp);
                            }
                        }
                    }

                }
                //通过Ck来确定Lk
                else
                {
                    L0.Clear();
                    for (int i = 0; i < C0.Count; i++)
                    {
                        itemAndSup temp = (itemAndSup)C0[i];
                        if (temp.sup >= minSup)
                            L0.Add(temp);
                    }
                }
                //对L0排序
                { }

                //更新L的视图
                {
                    if (L0.Count != 0)
                    {
                        this.LResultView.Items.Clear();
                        this.LResultView.Items.Add("项集\t支持度计数\n");
                        for (int i = 0; i < L0.Count; i++)
                        {
                            ArrayList items = ((itemAndSup)L0[i]).items;
                            int sup = ((itemAndSup)L0[i]).sup;
                            string LResultLine = "";
                            for (int j = 0; j < items.Count; j++)
                            {
                                LResultLine = LResultLine + items[j].ToString() + ",";
                            }
                            LResultLine = LResultLine + "\t" + sup + "\n";
                            this.LResultView.Items.Add(LResultLine);
                        }
                    }
                    else
                    {
                        this.LResultView.Items.Clear();
                        this.LResultView.Items.Add("项集\t支持度计数\n");
                        for (int i = 0; i < OldL.Count; i++)
                        {
                            ArrayList items = ((itemAndSup)OldL[i]).items;
                            int sup = ((itemAndSup)OldL[i]).sup;
                            string LResultLine = "";
                            for (int j = 0; j < items.Count; j++)
                            {
                                LResultLine = LResultLine + items[j].ToString() + ",";
                            }
                            LResultLine = LResultLine + "\t" + sup + "\n";
                            this.LResultView.Items.Add(LResultLine);
                        }
                    }
                }
                //更新说明
                {
                    if (L0.Count != 0)
                        this.Msg.Text = "比较候选支持度计数与最小支持度计数";
                    else
                    {
                        this.Msg.Text = "由于L为空，算法终止";
                        this.Next.Text = "完成（重新开始）";
                        finish = true;
                    }

                }
            }
            //计算C
            else
            {
                //通过将Lk-1与自身连接产生Ck
                C0.Clear();
                for (int i = 0; i < L0.Count; i++)
                {
                    ArrayList items0 = ((itemAndSup)L0[i]).items;
                    ArrayList addItem = new ArrayList();
                    for (int j = 0; j < L0.Count; j++)
                    {
                        if (j == i)
                            continue;
                        ArrayList items1 = ((itemAndSup)L0[j]).items;
                        for (int k = 0; k < items1.Count; k++)
                        {
                            /*
                            if (items0.Contains(items1[k]))
                                continue;
                            */
                            //改进
                            if (((string)items1[k]).CompareTo((string)items0[items0.Count - 1]) <= 0)
                                continue;
                            if (addItem.Contains(items1[k]))
                                continue;