R 列表另存为引用列表

Question

想要将 recommenderlab 预测列表保存为“”分隔列表的列表。我有一个相同的问题，但这里想稍微扩展一下。

我已经尝试了几种方法并在下面找到了相关方法，但坚持了一个简单的步骤，将输出放入“”逗号分隔的脚本中。

library("recommenderlab")
library(stringi)
data("MovieLense")
MovieLense100 <- MovieLense[rowCounts(MovieLense) >100,]
MovieLense100
train <- MovieLense100[1:50]
rec <- Recommender(train, method = "UBCF")
rec
pre <- predict(rec, MovieLense100[101:105], n = 10)
as(pre, "list")

list1 = as(pre, "list")

cat(paste0(shQuote(list1[["291"]]),collapse=","))

上面给出了给定用户：

"Titanic (1997)","Contact (1997)","Alien (1979)","Amadeus (1984)","Godfather, The (1972)","Aliens (1986)","Sting, The (1973)","American Werewolf in London, An (1981)","Schindler's List (1993)","Glory (1989)"

我想将用户和电影放在数据框中，其中第一列是用户，第二列是上述串联形式的电影

Answer 1

鉴于 cat(paste0(shQuote(list1[["291"]]),collapse=",")) 生成电影推荐字符串，可以执行以下操作将其转换为标有名称的数据框：

movies <- cat(paste0(shQuote(list1[["291"]]),collapse=","))
theData <- data.frame(name="Santhosh",movies,stringsAsFactors=FALSE)

另一种方法是将每部电影保存为输出数据框中的单独列，这样可以更轻松地使用 R 中的数据，而无需多次解析电影列表。 tidyverse（即 tidyr 和 dplyr）可用于生成此数据框。

library(tidyr)
library(dplyr)
recommendedMovies <- c("Titanic (1997)","Contact (1997)","Alien (1979)","Amadeus (1984)","Godfather, The (1972)","Aliens (1986)","Sting, The (1973)","American Werewolf in London, An (1981)","Schindler's List (1993)","Glory (1989)")
theData <- data.frame(name="Santhosh",
                      rank=1:length(recommendedMovies),
                      movies=recommendedMovies,stringsAsFactors=FALSE)
theData %>% group_by(name) %>%
spread(.,rank,movies,sep="movie")

...输出：

> theData %>% group_by(name) %>%
+ spread(.,rank,movies,sep="movie")
# A tibble: 1 x 11
# Groups:   name [1]
  name  rankmovie1 rankmovie2 rankmovie3 rankmovie4 rankmovie5 rankmovie6 rankmovie7 rankmovie8 rankmovie9
  <chr> <chr>      <chr>      <chr>      <chr>      <chr>      <chr>      <chr>      <chr>      <chr>     
1 Sant… Titanic (… Contact (… Alien (19… Amadeus (… Godfather… Aliens (1… Sting, Th… American … Schindler…
# ... with 1 more variable: rankmovie10 <chr>
>

R 列表另存为引用列表

R list save as quoted list

r

recommenderlab