## Friday, December 21, 2007

### [TECH] Finding frequent itemsets faster than FP-Growth algorithm

I wanted to implement my prime-number mapping intersection algorithm into the TM(Transaction Mapping) Algorithm, I got the FP-Tree implementation from PERL FP Tree and was trying to test this on a data of around 300,000 records, it works till 10,000 records with support and confidence of 0.8 and 0.9 and fails if the number of records > 20,000. I'm not sure if its a perl bug but the following code which is the cause of the problem seems difficult to understand



===================================================================
@association_rules = map $_->[0], (sort {$b->[1] <=> $a->[1]} (map [$_, $_->confidence], @association_rules)); ===================================================================   I tried to bless the reference$_ but it did'nt work. The following is the error it gives.