【发布时间】：2022-01-06 19:02:12
【问题描述】：
我正在尝试整理一些数据。我尝试将随机字符串归类为数字。
table <- "x count
1 k
2 2k
3 k1e
4 k2e
5 2k1e
6 k2
7 ke
8 k3e
9 1ek
10 ek
11 x2k
12 xk2e
13 xk1e
14 k2e1m
15 xk
16 1mk1e
17 k1m
18 k1e1m
19 1ek1m
20 k2m
21 1mk
22 xk1m
23 k1e2
24 1e
25 x
26 x1m
27 f1m
28 fk
29 f
30 fk1m
31 ff
32 ff2m
33 f2m
34 2m
35 1m
36 2s
37 f2k
38 ffk1m
39 f2k1m
40 kx
41 xxk
42 2k2e
43 k1m2
44 kf1m
45 1k1e
46 1k2e
47 1k1e1m
48 1k1m
49 1k2m
50 1k1d
51 2k1m
52 3k
53 kk
54 2k2m
55 2kk
56 kk1e
57 2kx
58 xk2k
59 x2k2e
60 k1e2m
61 k1mk
62 k3m
63 k2x
64 k1me
65 xk2m
66 1mfl
67 3m
68 fk2m
69 fk1e
70 fk1e1m
71 ffkk
72 xkf1m
73 ffk"
#Create a dataframe with the above table
df <- read.table(text=table, header = TRUE)
df
这是嵌套的 ifelse 语句：
df$new <- ifelse(grepl("k", df$old, ignore.case = T), "1",
ifelse(grepl("2k", df$old, ignore.case = T), "2",
ifelse(grepl("k1e", df$old, ignore.case = T), "1",
ifelse(grepl("k2e", df$old, ignore.case = T), "1",
ifelse(grepl("2k1e", df$old, ignore.case = T), "2",
ifelse(grepl("k2", df$old, ignore.case = T), "2",
ifelse(grepl("ke", df$old, ignore.case = T), "1",
ifelse(grepl("k3e", df$old, ignore.case = T), "1",
ifelse(grepl("1ek", df$old, ignore.case = T), "1",
ifelse(grepl("ek", df$old, ignore.case = T), "1",
ifelse(grepl("x2k", df$old, ignore.case = T), "2",
ifelse(grepl("xk2e", df$old, ignore.case = T), "1",
ifelse(grepl("xk1e", df$old, ignore.case = T), "3",
ifelse(grepl("k2e1m", df$old, ignore.case = T), "1",
ifelse(grepl("xk", df$old, ignore.case = T), "2",
ifelse(grepl("1mk1e", df$old, ignore.case = T), "1",
ifelse(grepl("k1m", df$old, ignore.case = T), "2",
ifelse(grepl("k1e1m", df$old, ignore.case = T), "1",
ifelse(grepl("1ek1m", df$old, ignore.case = T), "2",
ifelse(grepl("k2m", df$old, ignore.case = T), "2",
ifelse(grepl("1mk", df$old, ignore.case = T), "1",
ifelse(grepl("xk1m", df$old, ignore.case = T), "2",
ifelse(grepl("k1e2", df$old, ignore.case = T), "1",
ifelse(grepl("1e", df$old, ignore.case = T), "4",
ifelse(grepl("x", df$old, ignore.case = T), "1",
ifelse(grepl("x1m", df$old, ignore.case = T), "2",
ifelse(grepl("f1m", df$old, ignore.case = T), "1",
ifelse(grepl("fk", df$old, ignore.case = T), "2",
ifelse(grepl("f", df$old, ignore.case = T), "2",
ifelse(grepl("fk1m", df$old, ignore.case = T), "1",
ifelse(grepl("ff", df$old, ignore.case = T), "2",
ifelse(grepl("ff2m", df$old, ignore.case = T), "2",
ifelse(grepl("f2m", df$old, ignore.case = T), "1",
ifelse(grepl("2m", df$old, ignore.case = T), "2",
ifelse(grepl("1m", df$old, ignore.case = T), "2",
ifelse(grepl("2s", df$old, ignore.case = T), "6",
ifelse(grepl("f2k", df$old, ignore.case = T), "2",
ifelse(grepl("ffk1m", df$old, ignore.case = T), "2",
ifelse(grepl("f2k1m", df$old, ignore.case = T), "2",
ifelse(grepl("kx", df$old, ignore.case = T), "1",
ifelse(grepl("xxk", df$old, ignore.case = T), "2",
ifelse(grepl("2k2e", df$old, ignore.case = T), "2",
ifelse(grepl("k1m2", df$old, ignore.case = T), "1",
ifelse(grepl("kf1m", df$old, ignore.case = T), "2",
ifelse(grepl("1k1e", df$old, ignore.case = T), "2",
ifelse(grepl("1k2e", df$old, ignore.case = T), "5",
ifelse(grepl("1k1e1m", df$old, ignore.case = T), "2",
ifelse(grepl("1k1m", df$old, ignore.case = T), "2",
ifelse(grepl("1k2m", df$old, ignore.case = T), "2",
ifelse(grepl("1k1d", df$old, ignore.case = T), "1",
ifelse(grepl("2k1m", df$old, ignore.case = T), "2",
ifelse(grepl("3k", df$old, ignore.case = T), "2",
ifelse(grepl("kk", df$old, ignore.case = T), "2",
ifelse(grepl("2k2m", df$old, ignore.case = T), "1",
ifelse(grepl("2kk", df$old, ignore.case = T), "2",
ifelse(grepl("kk1e", df$old, ignore.case = T), "2",
ifelse(grepl("2kx", df$old, ignore.case = T), "4",
ifelse(grepl("xk2k", df$old, ignore.case = T), "2",
ifelse(grepl("x2k2e", df$old, ignore.case = T), "2",
ifelse(grepl("k1e2m", df$old, ignore.case = T), "1",
ifelse(grepl("k1mk", df$old, ignore.case = T), "2",
ifelse(grepl("k3m", df$old, ignore.case = T), "2",
ifelse(grepl("k2x", df$old, ignore.case = T), "1",
ifelse(grepl("k1me", df$old, ignore.case = T), "2",
ifelse(grepl("xk2m", df$old, ignore.case = T), "2",
ifelse(grepl("1m(fkllenfromnestkbove)", df$old, ignore.case = T), "1",
ifelse(grepl("3m", df$old, ignore.case = T), "4",
ifelse(grepl("fk2m", df$old, ignore.case = T), "2",
ifelse(grepl("fk1e", df$old, ignore.case = T), "1",
ifelse(grepl("fk1e1m", df$old, ignore.case = T), "8",
ifelse(grepl("ffkk", df$old, ignore.case = T), "2",
ifelse(grepl("xkf1m", df$old, ignore.case = T), "1",
ifelse(grepl("ffk", df$old, ignore.case = T), "2", "Other"
)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
这会导致错误：
Error: unexpected ')' in "
输出看起来与此类似，但行数更多：
table <- "x count number
1 k 1
2 2k 2
3 k1e 1
4 k2e 1
5 2k1e 2
6 k2 2
7 ke 1
8 k3e 1
9 1ek 1
10 ek 1"
无论我添加或删除多少个括号，此错误仍然存在。我在其他网站上发现了一些人们遇到此问题的主题，但没有解决方案。
任何建议将不胜感激。
【问题讨论】：
-
或
case_when，如果顺序很重要。 -
整个方法极易出错且不必要的复杂。我建议您宁愿创建一个查找列表 agsint 您将匹配您的数据并替换这些值。如果您能提供一个我们可以使用的可重现的示例，那将很有帮助。
-
有一个limit to the number of nested ifelse() calls you can make。我最好在这里使用不同的功能。如果您包含一个简单的reproducible example，其中包含可用于测试和验证替代解决方案的示例输入和所需输出，则更容易为您提供帮助。
-
我会注意到您的第一个条件检查是否存在
k并生成结果"1"。只有在没有k时才会检查所有后续条件。但是许多后续条件都包含k，因此任何包含k的后续条件都不会是TRUE，因为它们被第一个grepl("k")抢占了。 -
@jl748795
grepl用于查找 inside 字符串。如果要测试字符串x是否在其中任何位置包含k，请使用grepl("k", x)。如果你想测试一个字符串是否正好是"k"，你可以使用x == "k"或"k" %in% x。 （虽然我猜你现在明白了，但这里有其他选择。）
标签： r if-statement nested grepl tidy