将特定列“单词”替换为数字或空白

时间:2011-04-10 15:40:57

标签: r replace numbers

输入表

Patients  Hospital   Drug   Response
1         AAA        a      Good
1         AAA        a      Bad
2         BBB        a      Bad
3         CCC        b      Good
4         CCC        c      Bad
5         DDD        e      undefined 

输出文件

Patients  Hospital   Drug   Response
1         AAA        a      1
1         AAA        a      -1
2         BBB        a      -1
3         CCC        b      1
4         CCC        c      -1
5         DDD        e       

如何将一列中的3个文本替换为数字和空白?

“好在Reponse栏”到“1” “在Reponse栏中不好”到“-1” “在Reponse栏中未定义”至“”

数据:

structure(list(Patients = c(1L, 1L, 2L, 3L, 4L, 5L), Hospital = structure(c(1L, 
1L, 2L, 3L, 3L, 4L), .Label = c("AAA", "BBB", "CCC", "DDD"), class = "factor"), 
    Drug = structure(c(1L, 1L, 1L, 2L, 3L, 4L), .Label = c("a", 
    "b", "c", "e"), class = "factor"), Response = structure(c(2L, 
    1L, 1L, 2L, 1L, 3L), .Label = c("Bad", "Good", "undefined"
    ), class = "factor")), .Names = c("Patients", "Hospital", 
"Drug", "Response"), class = "data.frame", row.names = c(NA, 
-6L))

4 个答案:

答案 0 :(得分:16)

您可以通过更改因子Response的标签来执行此操作:

> within(df, Response <- factor(Response, labels = c(-1, 1, "")))
  Patients Hospital Drug Response
1        1      AAA    a        1
2        1      AAA    a       -1
3        2      BBB    a       -1
4        3      CCC    b        1
5        4      CCC    c       -1
6        5      DDD    e         

答案 1 :(得分:5)

凯瑟琳,您的问题仍然可以通过R中的一本非常基本的教科书来回答。请参阅Dirk在previous question中的评论。

<强>答案

如果d是您的数据框,则:

d[d$Response == "Good",]$Response = 1
d[d$Response == "Bad",]$Response = -1
d[d$Response == "undefined",]$Response = ""

我猜(我可能错了)“Undefined”缺少数据。在这种情况下,请使用NA而不是空白。任何基本的R书都会描述NA

答案 2 :(得分:2)

如果您的数据位于数据框df

df$Response[df$Response == "Good"] <- 1
df$Response[df$Response == "Bad"] <- -1
df$Response[df$Response == "undefined"] <- ""

答案 3 :(得分:2)

您可以使用简单的ifelse()语句。

cath <- data.frame(nmbrs = runif(10), words = sample(c("good", "bad"), 10, replace = TRUE))
cath$words <- ifelse(cath$words == "good", 1, ifelse(cath$words == "bad", -1, ""))