Question

下面是一个称为function的{{1}}，但仅在特定的数据帧名称上有效。简而言之，我在理解如何操作change_names函数以使其可以处理不同的数据帧名称方面遇到问题。

当我在assign中读取文件时，function基本上会更改文件列上的名称。例如，一个文件可能具有列名称for loop，应为'A'，而另一个文件可能具有列名称'X'，其列名称也应为'D'。

我尝试了几种不同的方法来实际更改原始数据帧'X'，但是我需要能够在其他数据帧上使用该功能。

'tempPullList'

再次，现在我只能在数据帧称为“ tempPullList”时执行此操作，我需要能够对另一个数据帧进行操作。

我在编写函数，尤其是在函数内分配变量方面还很陌生。我希望此功能尽可能多变。我目前正在努力将#====example different files==== file1 <- data.frame(A = rep(1:10), Y = rep(c("Yellow","Red","Purpule","Green","Blue"), 2), Z = rep(c("Drink", "Food"), 5)) file2 <- data.frame(D = rep(1:10), B = rep(c("Brown","Pink","Purpule","Green","Blue"), 2), Z = rep(c("Drink", "Food"), 5)) file3 <- data.frame(X = rep(1:10), B = rep(c("Brown","Pink","Purpule","Green","Blue"), 2), C = rep(c("Drink", "Food"), 5)) file_list <- list(file1, file2, file3) #====Package Bank==== library(data.table) library(dplyr) #====Function==== change_names <- function(x){ #a list of columns to be renamed #through out the files chgCols <- c("A", "B", "C", "D") #the names the columns will be changed to namekey <- c(A = "X", B = "Y", C = "Z", D = "X") chgCols <- match(chgCols, colnames(x)) #find any unwanted column indexes in data frame chgCols <- colnames(x[, chgCols[!is.na(chgCols)]]) #match indexes to column names w/o NA's x <- x %>% #rename associated columns plyr::rename(namekey[chgCols]) #from 'namekey' in dataframe assign('tempPullList', x, envir = .GlobalEnv) } #====Read in Files==== PullList <- data.frame() for(file in 1:length(file_list)){ tempPullList <- data.frame(file_list[file]) print(file) change_names(x = tempPullList) PullList <- rbindlist(list(PullList, tempPullList), fill = T) }和chgCols用作输入。因此，对此的任何建议也将有所帮助

Answer 1

示例数据：

column_name_lookup <- data.frame(orig = c("a","b","c","d"),
                                 new = c("X","Y","z","X"),
                                 stringsAsFactors = FALSE)

test_df <- data.frame(a = 1:5,
                      c = 2:6,
                      b = 3:7,
                      e = 4:8,
                      d = 5:9)

  a c b e d
1 1 2 3 4 5
2 2 3 4 5 6
3 3 4 5 6 7
4 4 5 6 7 8
5 5 6 7 8 9

更改名称的代码：

new_names <- column_name_lookup$new[match(names(test_df),column_name_lookup$orig)]

names(test_df) <- ifelse(is.na(new_names),names(test_df),new_names)

  X z Y e X
1 1 2 3 4 5
2 2 3 4 5 6
3 3 4 5 6 7
4 4 5 6 7 8
5 5 6 7 8 9

r-更改函数中的变量列名称

1 个答案: