使用SAC的共现矩阵? [英] Co-occurrence matrix using SAC?

问题描述

我有以下数据框"x"

I have the following data frame 'x'

id,item,volume
a,c1,2
a,c2,3
a,c3,2
a,c4,1
a,c5,4
b,c6,6
b,c1,2
b,c3,1
b,c2,6
b,c4,4
c,c2,5
c,c8,6
c,c9,2
d,c1,1
e,c3,7
e,c2,3
e,c1,2
e,c9,5
e,c4,1
f,c1,7
f,c3,1

第一列是客户的ID，第二列是客户购买的商品的ID，第三列是购买的商品的数量.我正在尝试创建一个共现矩阵，它是一个具有8行和8列的正方形矩阵，其中8是不同项目的数量.

The first column is the id of a customer, the second column is the id of an item that customer bought and the third column is the number of those items bought. I'm trying to create a co-occurrence matrix which is a square matrix with 8 rows and columns, 8 being the number of distinct items.

n = length(unique(x$cid))

这可以通过SAC范例来完成吗?对于每个id，我需要通过为每个组合添加+1来更新上述矩阵.例如，对于具有项目c1，c2，c3，c4，c6的用户"b"，矩阵中第2、3、4和第2列的第一行；对于所有用户，应将6递增1，依此类推.我无法将其投放到此框架中.任何帮助表示赞赏.

Could this be done through a SAC paradigm? For every id, I need to update the above matrix by adding +1 for every combination. For example for user 'b' with items c1,c2,c3,c4,c6, the 1st row in the matrix for columns 2,3,4 & 6 should be incremented by 1 and so on for all users. I'm unable to cast it into this framework. Any help much appreciated.

推荐答案

正如@joran提到的那样，不清楚您真正想要的是什么.但是，如果我理解正确(可能无法正确理解)，我想提出一条替代路线.我想您想将商品矩阵转化为商品，并用数字表示商品共享客户的次数?

As @joran mentioned its kind of unclear what you really want. But If I understand correctly(probably not) I would like to propose an alternate route. I think you want a matrix of items to items with numbers representing the number of times the items share a customer?

如果是这样，

library(igraph)
library(tnet)
id_item<-cbind(
i=c(1,1,2,2,2,2,2,3,4,5,5,5,6,6,7,8),  #items
p=c(1,2,1,2,3,4,5,2,3,4,5,6,6,7,8,8))  #customers
item_item<-projecting_tm(id_item, method="sum")
item_item <- tnet_igraph(item_item,type="weighted one-mode tnet")
itemmat<-get.adjacency(item_item,attr="weight")
itemmat  #8x8 martrix of items to items

#     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
#[1,]    0    2    1    0    0    0    0    0
#[2,]    2    0    1    1    2    0    0    0
#[3,]    1    1    0    0    0    0    0    0
#[4,]    0    1    0    0    0    0    0    0
#[5,]    0    2    0    0    0    1    0    0
#[6,]    0    0    0    0    1    0    0    0
#[7,]    0    0    0    0    0    0    0    1
#[8,]    0    0    0    0    0    0    1    0

如果您还需要考虑购买商品(数量)的次数，那么可以轻松地将其添加到此代码中.

If you need to take number of times the item was bought (volume) into account too then this is easily added into this code.

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