结合 gsub() 并使用变量名作为 R 中的列

Question

我希望有人能帮助我:)

我有一个包含大约 1000 列的数据框。其中，我有这样命名的列： X1,X2,X3,X4,X5,X6 等... Y1,Y2,Y3,Y4,Y5,Y6 等...

df <- data.frame("X1" = c("Yes","No","Yes","NA","NA","NA","Yes","No","Yes","NA","NA","NA","NA"),
                "X2" = c("Yes","NA","NA","NA","NA","Yes","NA","NA","NA","NA","Yes","NA","NA"), 
                "X3" = c("Yes","NA","NA","NA","Yes","No","Yes","NA","Yes","NA","NA","NA", "Yes"),
                "X4" = c("Yes","No","Yes","NA","NA","NA","Yes","No","Yes","NA","NA","NA","NA"),
                "X5" = c("Yes","NA","NA","NA","NA","Yes","NA","NA","NA","NA","Yes","NA","NA"), 
                "X6" = c("Yes","NA","NA","NA","Yes","No","Yes","NA","Yes","NA","NA","NA", "Yes"),
                "Y1" = c("Yes","No","Yes","NA","NA","NA","Yes","No","Yes","NA","NA","NA","NA"),
                "Y2" = c("Yes","NA","NA","NA","NA","Yes","NA","NA","NA","NA","Yes","NA","NA"), 
                "Y3" = c("Yes","NA","NA","NA","Yes","No","Yes","NA","Yes","NA","NA","NA", "Yes"),
                "Y4" = c("Yes","No","Yes","NA","NA","NA","Yes","No","Yes","NA","NA","NA","NA"),
                "Y5" = c("Yes","NA","NA","NA","NA","Yes","NA","NA","NA","NA","Yes","NA","NA"), 
                "Y6" = c("Yes","NA","NA","NA","Yes","No","Yes","NA","Yes","NA","NA","NA", "Yes"))

在某些列中，我将“是”替换为 1，将“否”替换为 0，并将其他任何内容替换为 NA。

我试过这个：

names = c("X","Y")

for (name in names){
  try(
    for (j in 1:6){
      j <- toString(j)
      colname <- paste(name , j, sep="")
      df$colname <- gsub("Yes", as.integer(1), df$colname)
      df$colname <- gsub("No", as.integer(0), df$colname)
    })}

但是，这不起作用，抛出错误消息：

Error in `$<-.data.frame`(`*tmp*`, "colname", value = character(0)) : replacement has 0 rows, data has 13

我的第一个问题是：为什么列名没有正确引用？
第二个问题是：如何将这些列中不是 0 或 1 的任何内容替换为“NA”？

这可能是我忽略的一个非常简单的事情，但我不太清楚如何去做。任何帮助将不胜感激。

非常感谢，富有

Answer 1

我不会在这里使用循环或 gsub，你可以使用这个：

df[] <- lapply(df, function(x) x <- car::recode(x, "'Yes'=1; 'No'=0; 'NA'=NA"))

这会遍历数据框中的每一列并根据需要重新编码值。如果以后得到更多的值，这也更容易扩展。

如果你只想要某些列，你可以这样修改：

df[, col_list] <- lapply(df[, col_list], function(x) x <- car::recode(x, "'Yes'=1; 'No'=0; 'NA'=NA"))

其中 col_list 是您要更改的变量的向量。您可以使用 col_list <- grep('^X|Y', names(df), value = T)

为他们搜索

Answer 2

由于您的数据只有 'Yes'、'No' 和 'NA' 值，您也可以直接替换它们。

#Column numbers to replace
cols <- grep('^[XY]\d+', names(df))
#Replace "NA" with real NA
df[cols][df[cols] == 'NA'] <- NA
#Replace "Yes" with 1
df[cols][df[cols] == 'Yes'] <- 1
#Replace "No" with 0
df[cols][df[cols] == 'No'] <- 0
#Change dataframe type.
df <- type.convert(df)
df
#   X1 X2 X3 X4 X5 X6 Y1 Y2 Y3 Y4 Y5 Y6
#1   1  1  1  1  1  1  1  1  1  1  1  1
#2   0 NA NA  0 NA NA  0 NA NA  0 NA NA
#3   1 NA NA  1 NA NA  1 NA NA  1 NA NA
#4  NA NA NA NA NA NA NA NA NA NA NA NA
#5  NA NA  1 NA NA  1 NA NA  1 NA NA  1
#6  NA  1  0 NA  1  0 NA  1  0 NA  1  0
#7   1 NA  1  1 NA  1  1 NA  1  1 NA  1
#8   0 NA NA  0 NA NA  0 NA NA  0 NA NA
#9   1 NA  1  1 NA  1  1 NA  1  1 NA  1
#10 NA NA NA NA NA NA NA NA NA NA NA NA
#11 NA  1 NA NA  1 NA NA  1 NA NA  1 NA
#12 NA NA NA NA NA NA NA NA NA NA NA NA
#13 NA NA  1 NA NA  1 NA NA  1 NA NA  1

如果您使用的 R < 4.0.0，您首先需要将数据转换为字符。

df[] <- lapply(df, as.character)

结合 gsub() 并使用变量名作为 R 中的列

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