“Zero frequent items” when using the eclat to mine frequent itemsets

问题

So I want to find patterns and "clusters" based on what items that are bought together, and according to the wiki for eclat:

The Eclat algorithm is used to perform itemset mining. Itemset mining let us find frequent patterns in data like if a consumer buys milk, he also buys bread. This type of pattern is called association rules and is used in many application domains.

Though, when I use the eclat in R, i get "zero frequent items" and "NULL" when when retrieving the results through tidLists. Anyone can see what I am doing wrong?

The full dataset: https://pastebin.com/8GbjnHK2

Each row is a transactions, containing different items in the columns. Quick snap of the data:

3060615;;;;;;;;;;;;;;;
3060612;3060616;;;;;;;;;;;;;;
3020703;;;;;;;;;;;;;;;
3002469;;;;;;;;;;;;;;;
3062800;;;;;;;;;;;;;;;
3061943;3061965;;;;;;;;;;;;;;

The code

trans = read.transactions("Transactions.csv", format = "basket", sep = ";")

f <- eclat(trans, parameter = list(supp = 0.1, maxlen = 17, tidLists = TRUE))

dim(tidLists(f))

as(tidLists(f), "list")

Could it be due to the data structure? In that case, how should I change it? Furthermore, what do I do to get the suggested itemsets? I couldn't figure that out from the wiki.

EDIT: I used 0.004 for supp, as suggested by @hpesoj626. But it seems like the function is grouping the orders/users and not the items. I don't know how to export the data, so here is a picture of the tidLists:

回答1:

The problem is that you have set your support too high. Try adjusting supp say, supp = .001, for which we get

dim(tidLists(f))

# [1]   928 15840

For your data set, the highest support is 0.08239 which is below 0.1. That is why you are getting no results with supp = 0.1.

inspect(head(sort(f, by = "support"), 10))

#      items             support count
# [1]  {3060620}         0.08239 1305 
# [2]  {3060619}         0.07260 1150 
# [3]  {3061124}         0.05688  901 
# [4]  {3060618}         0.05663  897 
# [5]  {4027039}         0.04975  788 
# [6]  {3060617}         0.04564  723 
# [7]  {3061697}         0.04306  682 
# [8]  {3060619,3060620} 0.03087  489 
# [9]  {3039715}         0.02727  432 
# [10] {3045117}         0.02708  429

来源：https://stackoverflow.com/questions/50552493/zero-frequent-items-when-using-the-eclat-to-mine-frequent-itemsets

标签

data-mining