如何读取 R feom 数据框中的事务？

Posted 2023-03-23

【中文标题】如何读取 R feom 数据框中的事务？

【英文标题】：How to read.transactions in R feom data frame?

【发布时间】：2019-10-07 12:38:24

【问题描述】：

我有以下任务。我有 50M 的交易行。我无法将其导出到 .txt 文件，但我与 Hive 有连接，并且我创建了包含事务的表： Transcation_id 项目 1个 1乙 1℃ 2个 2个

我不能用

order_trans <- read.transactions(
  file = "(...)/trans2019.csv",
  format = "single",
  header=TRUE,
  sep = ",",
  cols=c("trans_id","item"),
  rm.duplicates = T,
  encoding = "UTF-16LE")

因为它减少了交易。

我也想做同样的事情，但是代替“文件”，我想放置我的数据框（trans_id，item），但它不起作用。 我也试过了：

trans = as(data.frame,"transactions") 但是先验算法给了我错误的规则

APPLE--> transaction_ID

谁能帮我解决这个问题？

【参考方案1】：

以下是手册页中的解决方案（请参阅“？交易”）：

## example 4: creating transactions from a data.frame with 
## transaction IDs and items (by converting it into a list of transactions first) 
a_df3 <- data.frame(
  TID = c(1,1,2,2,2,3),
  item=c("a","b","a","b","c", "b")
  )
a_df3
trans4 <- as(split(a_df3[,"item"], a_df3[,"TID"]), "transactions")
trans4
inspect(trans4)

## Note: This is very slow for large datasets. It is much faster to 
## read transactions using read.transactions() with format = "single".
## This can be done using an anonymous file.
write.table(a_df3, file = tmp <- file(), row.names = FALSE)
trans4 <- read.transactions(tmp, format = "single",
  header = TRUE, cols = c("TID", "item"))
close(tmp)
inspect(trans4)