Product usage combination in R

问题

I trying to figure out a way to get a list of product combinations with unique users in R. This is a follow up question to [Generate matrix of unique user-item cross-product combinations

df <- data.frame(Products=c('Product a', 'Product b', 'Product a', 
                            'Product c', 'Product b', 'Product c', 'Product d'),
                 Users=c('user1', 'user1', 'user2', 'user1', 
                         'user2','user3', 'user1'))

Output of df is:

   Products Users
1 Product a user1
2 Product b user1
3 Product a user2
4 Product c user1
5 Product b user2
6 Product c user3
7 Product d user1

The output I am looking for would be all three product combinations:

Product a/Product b/Product c - 3
Product a/Product b/Product d - 2
Product b/Product c/Product d - 3
...

Thanks again for your help.

回答1:

It looks like you want logical-OR treatment as the relation between users and each product set. In other words, you want to count how many unique users have any product in the set. Here's one way of doing it:

df <- data.frame(Products=c('Product a','Product b','Product a','Product c','Product b','Product c','Product d'),Users=c('user1','user1','user2','user1','user2','user3','user1'));
comb <- combn(unique(df$Products),3);
data.frame(comb=apply(comb,2,function(x) paste(levels(comb)[x],collapse='/')),num=apply(comb,2,function(x) length(unique(df$Users[as.integer(df$Products)%in%x]))));
##                            comb num
## 1 Product a/Product b/Product c   3
## 2 Product a/Product b/Product d   2
## 3 Product a/Product c/Product d   3
## 4 Product b/Product c/Product d   3

Edit: Logical-AND is trickier, since we need to test for the presence of every product for every user. I think I found a good solution using aggregate() and match():

data.frame(comb=apply(comb,2,function(x) paste(levels(comb)[x],collapse='/')),num=apply(comb,2,function(x) sum(aggregate(Products~Users,df,function(y) !any(is.na(match(x,as.integer(y)))))$Products)));
##                            comb num
## 1 Product a/Product b/Product c   1
## 2 Product a/Product b/Product d   1
## 3 Product a/Product c/Product d   1
## 4 Product b/Product c/Product d   1

来源：https://stackoverflow.com/questions/31092962/product-usage-combination-in-r

标签

list

combinations