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jkatam
Asked: 2024-04-21 00:39:32 +0800 CST

列名不符合预期

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我使用下面的代码来生成类数据帧的数字列的平均值和标准差。我期望新列的名称为 Age_mean、Age_std，而不是 Age.Age_mean、Age.Age_std。不知道为什么年龄。另外添加到列名称中

这是我使用的数据和代码

class <- structure(list(Name = c("Alfred", "Alice", "Barbara", "Carol", 
"Henry", "James", "Jane", "Janet", "Jeffrey", "John", "Joyce", 
"Judy", "Louise", "Mary", "Philip", "Robert", "Ronald", "Thomas", 
"William"), Sex = c("M", "F", "F", "F", "M", "M", "F", "F", "M", 
"M", "F", "F", "F", "F", "M", "M", "M", "M", "M"), Age = c(14, 
13, 13, 14, 14, 12, 12, 15, 13, 12, 11, 14, 12, 15, 16, 12, 15, 
11, 15), Height = c(69, 56.5, 65.3, 62.8, 63.5, 57.3, 59.8, 62.5, 
62.5, 59, 51.3, 64.3, 56.3, 66.5, 72, 64.8, 67, 57.5, 66.5), 
    Weight = c(112.5, 84, 98, 102.5, 102.5, 83, 84.5, 112.5, 
    84, 99.5, 50.5, 90, 77, 112, 150, 128, 133, 85, 112)), class = c("tbl_df", 
"tbl", "data.frame"), row.names = c(NA, -19L))


out1 <- list()

calc_mean <- function(data, vars, out) {
 
  vars <- syms(vars)
  print(vars)
  for (v in vars){
    print(v)
  out1[[v]] <- data %>% summarise('{{v}}_mean' := mean(!! v), '{{v}}_std' := sd(!! v))
  out2 <-  data.frame(out1)
  assign(out, out2, envir =.GlobalEnv)
  }

  return(out2)
}

calc_mean(data=class, vars=c('Age','Height'), out='want')

输出

  Age.Age_mean Age.Age_std Height.Height_mean Height.Height_std
1     13.31579    1.492672           62.33684          5.127075

1 个回答

  1. Best Answer

    添加它们可能是因为变量值（“年龄”和“身高”）。一种始终有效的方法是事后重命名输出，但这是另一种方法，使用所有整齐的动词而不for使用循环all_of。

    library(dplyr)

calc_mean_std <- function(df, vars){
  df %>% summarize(across(all_of(vars), \(x) mean(x), .names="{.col}_mean"), 
                   across(all_of(vars), \(x) sd(x), .names="{.col}_std"))
}

    输出

    take <- c("Age", "Height")

calc_mean_std(data, take)
# A tibble: 1 × 4
  Age_mean Height_mean Age_std Height_std
     <dbl>       <dbl>   <dbl>      <dbl>
1     13.3        62.3    1.49       5.13

    请注意，我不会命名数据类，因为它可能与class

    数据

    data <- structure(list(Name = c("Alfred", "Alice", "Barbara", "Carol", 
"Henry", "James", "Jane", "Janet", "Jeffrey", "John", "Joyce", 
"Judy", "Louise", "Mary", "Philip", "Robert", "Ronald", "Thomas", 
"William"), Sex = c("M", "F", "F", "F", "M", "M", "F", "F", "M", 
"M", "F", "F", "F", "F", "M", "M", "M", "M", "M"), Age = c(14, 
13, 13, 14, 14, 12, 12, 15, 13, 12, 11, 14, 12, 15, 16, 12, 15, 
11, 15), Height = c(69, 56.5, 65.3, 62.8, 63.5, 57.3, 59.8, 62.5, 
62.5, 59, 51.3, 64.3, 56.3, 66.5, 72, 64.8, 67, 57.5, 66.5), 
    Weight = c(112.5, 84, 98, 102.5, 102.5, 83, 84.5, 112.5, 
    84, 99.5, 50.5, 90, 77, 112, 150, 128, 133, 85, 112)), class = c("tbl_df", 
"tbl", "data.frame"), row.names = c(NA, -19L))

    '{{v}}_mean' := mean(!! v)当您分配名称时，您的命名发生在此处，而在此处

    data.frame(out1)当 tibbles 列表被转换为数据帧时。

    这是之后的中间输出data.frame(out1)

    $Age
# A tibble: 1 × 2
  Age_mean Age_std
     <dbl>   <dbl>
1     13.3    1.49

$Height
# A tibble: 1 × 2
  Height_mean Height_std
        <dbl>      <dbl>
1        62.3       5.13

    这被投射到例如Age.Age_mean

    您可以使用summarise('mean' := mean(!! v), 'std' := sd(!! v))以避免重复的名称，也可以names(out1) <- NULL在后面添加summarize以通过代码获得所需的结果。

    • 3

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