static ItemsetCollection AprioriCalc(ItemsetCollection db, double supportThreshold)
{
Itemset I = db.GetUniqueItems();
ItemsetCollection LitemList = new ItemsetCollection();
ItemsetCollection PitemList = new ItemsetCollection();
foreach (string item in I)
{
PitemList.Add(new Itemset()
{
item
});
}
int k = 2;
while (PitemList.Count != 0)
{
LitemList.Clear();
foreach (Itemset index in PitemList)
{
index.Support = db.FindSupport(index);
if (index.Support >= supportThreshold)
{
LitemList.Add(index);
itemList.Add(index);
}
}
PitemList.Clear();
PitemList.AddRange(Bit.FindSubsets(LitemList.GetUniqueItems(), k)); //get k-item subsets
k += 1;
}
return(itemList);
}
public static ItemsetCollection FindSubsets(Itemset itemset, int n)
{
ItemsetCollection subsets = new ItemsetCollection();
int subsetCount = (int)Math.Pow(2, itemset.Count);
for (int i = 0; i < subsetCount; i++)
{
if (n == 0 || GetOnCount(i, itemset.Count) == n)
{
string binary = DecimalToBinary(i, itemset.Count);
Itemset subset = new Itemset();
for (int charIndex = 0; charIndex < binary.Length; charIndex++)
{
if (binary[charIndex] == '1')
{
subset.Add(itemset[charIndex]);
}
}
subsets.Add(subset);
}
}
return(subsets);
}
static void DisplayItemSet(ItemsetCollection itemlist, List <AssociationRule> rule)
{
Console.WriteLine("Below is the Following: ItemSet using support of " + support + "%");
foreach (Itemset c in itemlist)
{
Console.Write(c.ToString() + " ,");
}
Console.WriteLine("\nBelow is the Following: ItemSet using confidence of " + confidence + "%");
foreach (AssociationRule c in rule)
{
Console.Write(c.ToString() + " ,");
}
Console.WriteLine("\n<Press Enter>");
Console.ReadLine();
}
static List <AssociationRule> Rules(ItemsetCollection db, ItemsetCollection L, double confidenceThreshold)
{
foreach (Itemset itemset in L)
{
ItemsetCollection subsets = Bit.FindSubsets(itemset, 0); //get all subsets
foreach (Itemset subset in subsets)
{
double confidence = (db.FindSupport(itemset) / db.FindSupport(subset)) * 100.0;
if (confidence >= confidenceThreshold)
{
AssociationRule rule = new AssociationRule();
rule.X.AddRange(subset);
rule.Y.AddRange(itemset.Remove(subset));
rule.Support = db.FindSupport(itemset);
rule.Confidence = confidence;
if (rule.X.Count > 0 && rule.Y.Count > 0)
{
allRules.Add(rule);
}
}
}
}
return(allRules);
}
public ItemsetCollection setData()
{
_items = new Itemset();
_items.Add("Game");
_items.Add("Water");
_items.Add("Monster");
_items.Add("Candy");
_items.Add("Shoes");
_items.Add("Controller");
_items.Add("PizzaRolls");
_items.Add("Console");
_db = new ItemsetCollection();
_db.Add(new Itemset()
{
_items[0], _items[2], _items[3], _items[5]
});
_db.Add(new Itemset()
{
_items[1], _items[4]
});
_db.Add(new Itemset()
{
_items[0], _items[2], _items[6]
});
_db.Add(new Itemset()
{
_items[1], _items[3], _items[4], _items[7]
});
_db.Add(new Itemset()
{
_items[0], _items[1], _items[6]
});
return(_db);
}