Question

我有以下名为cars的数据框

Brand      year     mpg        reputation      Luxury
Honda      2010     30            8.5            0.5
Honda      2011     28            8.5            0.6
Dodge      2010     20            6.5            0.6
Dodge      2011     23            7.0            0.7
Mercedes   2010     22            9.5            NA
Mercedes   2011     25            9.0            NA

我想用0.9 and 1.0之间的随机生成的实数代替NA

我正在尝试以下操作，但是它用数字0.9代替了NA

cars[is.na(cars)] <-  sample(0.9:1, sum(is.na(cars)),replace=TRUE)

数据表将如下所示：

Brand      year     mpg        reputation      Luxury
Honda      2010     30            8.5            0.5
Honda      2011     28            8.5            0.6
Dodge      2010     20            6.5            0.6
Dodge      2011     23            7.0            0.7
Mercedes   2010     22            9.5           *0.91*
Mercedes   2011     25            9.0           *0.97*

数据结构代码：

cars <- structure(list(Brand = c("Honda","Honda", "Dodge", "Dodge","Mercedes","Mercedes"), 
   year = c(2010L, 2011L,2010L, 2011L, 2010L, 2011L), 
   mpg = c(30L, 28L, 20L, 23L, 22L, 25L), reputation = c(8.5, 8.5, 6.5, 7L, 9.5, 9.5), Luxury = c(5L, 5.5, 6L, 6.5)), 
  class = "data.frame", row.names = c(NA, -4L))

Answer 1

使用runif代替sample：

cars[is.na(cars)] <-  runif(sum(is.na(cars)), min = 0.9, max = 1)

Answer 2

这是因为0.9:1仅给您一个数字0.9。尝试

0.9:1
#[1] 0.9

因此，它将这些数字替换为0.9。

假设您需要序列

vals <- seq(0.9, 1, 0.01)
vals
#[1] 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98 0.99 1.00

现在，我们可以按此顺序sample

df[is.na(df)] <- sample(vals, sum(is.na(df)), replace = TRUE)

df
#     Brand year mpg reputation Luxury
#1    Honda 2010  30        8.5   5.00
#2    Honda 2011  28        8.5   5.50
#3    Dodge 2010  20        6.5   6.00
#4    Dodge 2011  23        7.0   6.50
#5 Mercedes 2010  22        9.5   0.91
#6 Mercedes 2011  25        9.0   0.92

数据

df <- structure(list(Brand = structure(c(2L, 2L, 1L, 1L, 3L, 3L), 
.Label = c("Dodge", 
"Honda", "Mercedes"), class = "factor"), year = c(2010L, 2011L, 
2010L, 2011L, 2010L, 2011L), mpg = c(30L, 28L, 20L, 23L, 22L, 
25L), reputation = c(8.5, 8.5, 6.5, 7, 9.5, 9), Luxury = c(5, 
5.5, 6, 6.5, NA, NA)), class = "data.frame", row.names = c(NA, -6L))

用一定范围内的随机数替换数据框中的NA

2 个答案: