Question

我是R编程的新手，不幸的是我必须处理movieLens-1M数据。在这里，我想问一下如何在movies.dat中的delimiter [::]处拆分列。我试过这段代码：

> moviesDF<-read.delim("movies.dat", sep="|", header=F, stringsAsFactors=FALSE)
> str(moviesDF)
'data.frame':   3998 obs. of  3 variables:
 $ V1: chr  "1::Toy Story (1995)::Animation" "2::Jumanji (1995)::Adventure" "3::Grumpier Old Men (1995)::Comedy" "4::Waiting to Exhale (1995)::Comedy" ...
 $ V2: chr  "Children's" "Children's" "Romance" "Drama" ...
 $ V3: chr  "Comedy" "Fantasy" "" "" ...

所需的输出如下：

V1: Movie ID
V2: Title
V3: Genre

另外，我的目标是提供推荐系统

Answer 1

您可以在我的＆＃34; splitstackshape＆＃34;中尝试cSplit包。用法是：

library(splitstackshape)
cSplit(moviesDF, "V1", "::")
#            V2      V3 V1_1                     V1_2      V1_3
# 1: Children's  Comedy    1         Toy Story (1995) Animation
# 2: Children's Fantasy    2           Jumanji (1995) Adventure
# 3:    Romance            3  Grumpier Old Men (1995)    Comedy
# 4:      Drama            4 Waiting to Exhale (1995)    Comedy

Answer 2

问题在于导入功能。 read.delim(sep="|")未正确读取数据集，因为|仅限定V3中所需的不同值。您应该使用readLines导入数据集

moviesDF <- readLines("movies.dat")
moviesDF <- as.data.frame(do.call("rbind",strsplit(moviesDF,"::")),stringsAsFactors = FALSE)
names(moviesDF) <- c("V1","V2","V3")

在R中的MovieLens-1M数据中的分隔符[::]处拆分列

2 个答案: