df <- data.frame(x = c(1,1,1,2,2,3,3,3,4,5,5),
y = c("A","B","C","A","B","A","B","D","B","C","D"),
z = c(3,2,1,4,2,3,2,1,2,3,4))
df_new <- dcast(df, x ~ y, value.var = "z")
如果给定的示例数据中包含NA值,则dcast()函数会保留这些值。但是对于我的数据集,它却无效。因此,该函数将NA转换为零。为什么呢?
如何保留NA值? ml-latest-small.zip
r <- read.csv("ratings.csv")
m <- read.csv("movies.csv")
rm <- merge(ratings, movies, by="movieId")
umr <- dcast(rm, userId ~ title, value.var = "rating", fun.aggregate= sum)
提前感谢您。