apriori 與 fp-tree 探 勘頻繁項目集
DESCRIPTION
Apriori 與 FP-Tree 探 勘頻繁項目集. Frequent Pattern. 交易資料庫中頻繁的被一起購買的產品 可以做為推薦產品、銷售決策的依據 兩大演算法 Apriori FP-Tree. Apriori. scan. count. Large 1 itemsets 1 2 3 5. Apriori. L 1 1 2 3 5. generate C 2. scan. count. L 2 13 23 25 35. Apriori. L 2 13 23 25 35. - PowerPoint PPT PresentationTRANSCRIPT
APRIORI與 FP-TREE探勘頻繁項目集
Frequent Pattern
交易資料庫中頻繁的被一起購買的產品 可以做為推薦產品、銷售決策的依據 兩大演算法
AprioriFP-Tree
Apriori
Transaction ID Items Bought
1 1 3 4
2 2 3 5
3 1 2 3 5
4 2 5
Large 1 itemsets 1 2 3 5
Candidate 1 Count
1 2
2 3
3 3
4 1
5 3
scan
count
Apriori
C2
12
13
15
23
25
35
L1
1 2 3 5
C2 Count
12 1
13 2
15 1
23 2
25 3
35 2
scan
count
generate C2
TID Items Bought
1 1 3 4
2 2 3 5
3 1 2 3 5
4 2 5
L2
13232535
Apriori
C3
235
L2
13232535
C3 Count
235 2
scan
count
generate C3
TID Items Bought
1 1 3 4
2 2 3 5
3 1 2 3 5
4 2 5
L3
235
All frequent itemsets
13
235
Apriori缺點 效率不佳
IO時間過長Candidate過多
FP-Tree
FP-Tree
min_sup= 50% min_sup_count= 3
TID Items Bought
100 f,a,c,d,g,i,m,p
200 a,b,c,f,l,m,o
300 b,f,h,j,o
400 b,c,k,s,p
500 a,f,c,e,l,p,m,n
Items support
abcdefghijklmnop
3341141111123123
Items support
fcabmp
443333
FP-Tree
Items support
fcabmp
443333
TID Items Bought Frequent Items
100 f,a,c,d,g,i,m,p f,c,a,m,p
200 a,b,c,f,l,m,o f,c,a,b,m
300 b,f,h,j,o f,b
400 b,c,k,s,p c,b,p
500 a,f,c,e,l,p,m,n f,c,a,m,p
item head ofnode-links
f
c
a
b
m
p
Root
(order)Frequent Items
f,c,a,m,p
f,c,a,b,m
f,b
c,b,p
f,c,a,m,p
f:1
fc
c:1
a:1
m:1
p:1
f
f:2
c
c:2
a
a:2
b
b:1
m:1
m
item head ofnode-links
f
c
a
b
m
p
Root
(order)Frequent Items
f,c,a,m,p
f,c,a,b,m
f,b
c,b,p
f,c,a,m,p
f:4
c:3
a:3
m:2
p:2
b:1
m:1
b:1
c:1
b:1
p:1
item head ofnode-links
f
c
a
b
m
p
Root
f:4
c:3
a:3
m:2
p:2
b:1
m:1
b:1
c:1
b:1
p:1
Prefix {m}-ConditionalPattern Base
m ( acf:2 )(bacf:1 )
Frequent items | p
f:3 c:3 a:3
Root
f:3
item head ofnode-links
f
c
a
Prefix {m}-ConditionalPattern Base
m ( acf:2 )(bacf:1 )
c:3
a:3
Frequent Item Sets
fm:3, cm:3, am:3, fcm:3, fam:3, cam:3, fcam:3
item head ofnode-links
f
c
a
b
m
p
Root
f:4
c:3
a:3
m:2
p:2
b:1
m:1
b:1
c:1
b:1
p:1
Frequent Item Sets
cp:3, am:3, cam:3, fcam:3, fcam:3, fam:3, cm:3, fcm:3,fm:3, ca:3, fca:3, fa:3, fc:3