如何读取包含千位分隔符和零的特殊处理（在 R 中）的 .csv 数据？

Question

R version 3.2.2 on Ubuntu 14.04

I am trying to read in R .csv-data (two columns: "id" and "variable1") containing the thousand separator ",". So far no problem. I am using read.csv2 and the data looks like that:

> data <- read.csv2("data.csv", sep = ";", stringsAsFactors = FALSE, dec = ".")
> data[1000:1010, ]
     id        variable1
         1     2,001
     1,001     2,002
     1,002     2,001
     1,003     2,002
     1,004     2,001
     1,005     2,002
     1,006     2,001
     1,007     2,002
     1,008     2,001
     1,009     2,002
      1,01     2,001

After that first I tried to use gsub() to remove the commas:

data[, c("id", "variable1")] <- sapply(data[, c("id", "variable1")],
          function(x) {as.numeric(gsub("\\,","", as.character(x)))})
> data[1000:1010, ]
     id      variable1
        1      2001
     1001      2002
     1002      2001
     1003      2002
     1004      2001
     1005      2002
     1006      2001
     1007      2002
     1008      2001
     1009      2002
      101      2001

I think my problem is already obvious in the first output, because there is a thousand separator, but the "ending zeros" are missing. Like number "1000" is just displayed as "1" and "1010" as "1,01" for the "id"-variable in the data (also in the .csv-data). Of course, R can't identify this.

So my question is: Is there are way to tell R that every number must have three numbers after the thousand separator when reading in the data (or maybe after that), so that I have the correct numbers? The data should look like this:

> data[1000:1010, ]
     id      variable1
     1000      2001
     1001      2002
     1002      2001
     1003      2002
     1004      2001
     1005      2002
     1006      2001
     1007      2002
     1008      2001
     1009      2002
     1010      2001

Edit: Thanks you all for your answers. Unfortunately the suggestions will work for this example but not for my data, because I think I chose bad example rows. Other rows in the data can look like this:

       id1 variable1
1        1     2,001
999    999     1,102
1000     1     2,001
1001 1,001     2,002
1002 1,002     2,001

Of course, there is twice the number "1". The first is really a "1", but the second should be a "1000". But now I think I can't solve my problem with R. Maybe I need a better export of the original data, because the problem appears also in the .csv data.

Answer 1

删除逗号后，您可以执行以下操作：

data$id <- data$id*(10^(4-nchar(data$id)))

Answer 2

If "," is the only separator, ie all of the numbers are integers, you can set the dec argument of csv2 (or read.csv ) to "," and multiply by 1000:

data <- read.csv2(
  text = "id    ; variable1
          1     ; 2,001
          1,008 ; 2,001
          1,009 ; 2,002
          1,01  ; 2,001
          1,3   ; 2,0",
  sep = ";",
  stringsAsFactors = FALSE,
  header = TRUE,
  dec = "," )

.

> 1000*data
    id variable1
1 1000      2001
2 1008      2001
3 1009      2002
4 1010      2001
5 1300      2000
>