我如何将na.locf（）用于因子'输入'？

Question

我想根据ID本身前几年的组值在组变量中填充数据集的NA。代码的na.locf(newData, na.rm = TRUE)部分无效。我认为这是因为输入的不是数字。还是另一件事？有人知道如何解决此问题吗？

  for (i in my_data$ID){
    newData = my_data[my_data$ID==i,c('ID','Year', 'group')][3]
    na.locf(newData,na.rm = TRUE)

  } 

我的数据集非常大。但我将其作为我需要的示例：

structure(list(ID = c(1L, 2L, 3L, 1L, 1L, 1L), Year = c(2000L, 
2000L, 2001L, 2001L, 2002L, 2003L), Group = structure(c(2L, 3L, 
2L, 1L, 1L, 4L), .Label = c("", "\"A\"", "\"B\"", "\"C\""), class = "factor")), row.names = c(NA, 
6L), class = "data.frame")

结果应该是这样的：

structure(list(ID = c(1L, 1L, 1L, 1L, 2L, 2L), Year = c(2000L, 
2001L, 2002L, 2003L, 2000L, 2002L), Group = structure(c(1L, 1L, 
1L, 3L, 2L, 2L), .Label = c("\"A\"", "\"B\"", "\"C\""), class = "factor")), row.names = c(NA, 
6L), class = "data.frame")

Answer 1

正如我所说，您的问题很简单，您必须用NA替换空容器。

with(replace(df, df == '', NA), ave(Group, ID, FUN = zoo::na.locf))
#[1] "A" "B" "A" "A" "A" "C"

将其附加到df，

df$Group <- with(replace(df, df == '', NA), ave(Group, ID, FUN = zoo::na.locf))

给出，

  ID Year Group
1  1 2000   "A"
2  2 2000   "B"
3  3 2001   "A"
4  1 2001   "A"
5  1 2002   "A"
6  1 2003   "C"