r - 试图在 R 上的 ds 中查找没有导演的电影

Question

这是我试图运行以查找 director 不等于的行的代码NA：

nodir <- subset(x, director=="NA",
                    select = c(titles))

标签： r

Answer 1

Your problem is director=="NA". This logical comparison is defined to return NA. Because NA codes a missing value, NA == NA can be neither TRUE nor FALSE. You want is.na(director).