将字符向量切割成 R 中的名称、数字和 na 值

Question

我有一个以名称开头的字符向量，后跟数字和不带分隔符的 NA 值。 NA 值的长度为 3 (na.)，数字的长度可能不同，具体取决于它们是负数还是正数。例如。 -1.0 的长度为 4，0.7 的长度为 3。 输入：

mydata <- c("indigo-1.00.71.21.01.11.12.52.5na.na.1.21.01.01.0na.na.na.na.",
             "lago1.9-0.71.21.01.11.12.52.5na.na.1.21.01.01.0na.na.na.na.")

mydata 
[1] "indigo-1.00.71.21.01.11.12.52.5na.na.1.21.01.01.0na.na.na.na."
[2] "lago1.9-0.71.21.01.11.12.52.5na.na.1.21.01.01.0na.na.na.na."  

解决方案应该是一个如下所示的字符向量：

[1] "indigo" "-1.0" "0.7" "1.2" "1.0" "1.1" "1.1" "2.5" "2.5" "na." "na." "1.2" "1.0" "1.0" "1.0" "na." "na." "na." "na."
[2] "lago" "1.9" "-0.7" "1.2" "1.0" "1.1" "1.1" "2.5" "2.5" "na." "na." "1.2" "1.0" "1.0" "1.0" "na." "na." "na." "na."

Answer 1

使用base R，或许你可以试试下面的解决方案，使用regmatches()，即，

regmatches(mydata,gregexpr("[[:alpha:]]+|-?\\d.\\d|na\\.",mydata))

这样

> regmatches(mydata,gregexpr("[[:alpha:]]+|-?\\d.\\d|na\\.",mydata))
[[1]]
 [1] "indigo" "-1.0"   "0.7"    "1.2"    "1.0"    "1.1"    "1.1"    "2.5"    "2.5"    "na."    "na."    "1.2"    "1.0"   
[14] "1.0"    "1.0"    "na."    "na."    "na."    "na."   

[[2]]
 [1] "lago" "1.9"  "-0.7" "1.2"  "1.0"  "1.1"  "1.1"  "2.5"  "2.5"  "na."  "na."  "1.2"  "1.0"  "1.0"  "1.0"  "na."  "na." 
[18] "na."  "na.

Answer 2

使用stringr 和一些正则表达式很容易做到这一点：

mydata <- c("indigo-1.00.71.21.01.11.12.52.5na.na.1.21.01.01.0na.na.na.na.",
            "lago1.9-0.71.21.01.11.12.52.5na.na.1.21.01.01.0na.na.na.na.")

library(stringr)
str_extract_all(mydata, "^[[:alpha:]]+|-{0,1}\\d.\\d|na.")
#> [[1]]
#>  [1] "indigo" "-1.0"   "0.7"    "1.2"    "1.0"    "1.1"    "1.1"    "2.5"   
#>  [9] "2.5"    "na."    "na."    "1.2"    "1.0"    "1.0"    "1.0"    "na."   
#> [17] "na."    "na."    "na."   
#> 
#> [[2]]
#>  [1] "lago" "1.9"  "-0.7" "1.2"  "1.0"  "1.1"  "1.1"  "2.5"  "2.5"  "na." 
#> [11] "na."  "1.2"  "1.0"  "1.0"  "1.0"  "na."  "na."  "na."  "na."

^{由reprex package (v0.3.0) 于 2019 年 12 月 17 日创建}

请注意，结果是一个列表，其中的元素包含原始向量中每个元素的一个字符向量。你上面所说的确切形式在R中是不可能的