Question

我正在尝试基于满足其他两个变量lab_conf和diagnosis的任一条件来创建新变量PC_R。这是我正在使用的代码：

mutate(lab_conf = ifelse( (diagnosis == "confirmed")|(PC_R == "pos"), "pos", "neg"))

我得到的输出显示NA，它应该显示“ neg”，所以我只得到2个值； “ pos”或“ NA”。我希望根据指定的条件，将此新变量的值设置为“ pos”，“ neg”或NA，如果在两个条件下均为NA，则NA为NA。

这是我从dput(head(x))得到的：

structure(list(diagnosis = structure(c(16L, 16L, 16L, 3L, 16L, 
3L), .Label = c("*un-confirmed", "Cloted sample", "confirmed", 
"Hemolysed sampl", "inadequate sample", "rej (sample leaking)", 
"rej(Hemolyzed sample)", "rej(Hemolyzed)", "rej: sample Hemolyzed", 
"rej: sample leaking", "rej: sample leaking + Hemolyzed", "rej: sample leaking+not convnient tube", 
"repeat sample", "tf", "TF", "un-confirmed"), class = "factor"), 
    PC_R = structure(c(NA_integer_, NA_integer_, NA_integer_, 
    NA_integer_, NA_integer_, NA_integer_), .Label = c("clotted", 
    "hemolyzed", "neg", "not pos", "Not REQUIred", "OTHER", "pos", 
    "QNS", "rej", "repeat sample", "Sample broken", "tf", "TF"
    ), class = "factor"), lab_conf = c(NA, NA, NA, "pos", NA, 
    "pos")), .Names = c("diagnosis", "PC_R", "lab_conf"), row.names = c(NA, 
6L), class = "data.frame")

Answer 1

通常，当您提供样本数据时，您想要提供所有可能的结果。您提供的示例数据都是相同的。

我为您创建了一些示例数据，我认为这是您要使用的数据，然后执行该操作。

 library(dplyr)
temp2 <- structure(list(diagnosis = c("unconfirmed", "unconfirmed", "unconfirmed", "confirmed", "confirmed", "confirmed"), PC_R = c("pos", "neg",NA, "pos", "neg", NA)), row.names = c(NA, -6L), class = "data.frame")

temp2 %>% mutate(lab_conf = ifelse(diagnosis == "confirmed" | PC_R == "pos", "pos", "neg"))

   diagnosis PC_R lab_conf
1 unconfirmed  pos      pos
2 unconfirmed  neg      neg
3 unconfirmed <NA>     <NA>
4   confirmed  pos      pos
5   confirmed  neg      pos
6   confirmed <NA>      pos

Answer 2

使用%in%代替==，就像这样：

df = df %>%
  mutate(lab_conf = ifelse( (diagnosis %in% "confirmed") | (PC_R %in% "pos"), "pos", "neg"))

您遇到的问题是，如果其中一个操作数为==，则NA运算符将返回NA。同样，NA | FALSE返回NA。这两个事实是为什么您的OR语句将评估结果为NA的原因，这导致您的ifelse评估结果为NA。

ifelse语句被设置为如果该语句的值为TRUE，则返回“ pos”；如果该语句的值为FALSE，则返回“ neg”，但是如果该语句的值为NA，则ifelse不返回任何内容。这就是为什么您要获得NA。

使用%in%可以解决这个问题。

使用if_else或ifelse在多个条件下进行变异

2 个答案: