使用formattable过滤数据帧

Question

示例数据(从formattablegithub docs 修改):

df <- data.frame(
  id = 1:10,
  name = c("Bob", "Ashley", "James", "David", "Jenny", 
           "Hans", "Leo", "John", "Emily", "Lee"), 
  age = c(48, 47, 40, 28, 29, 29, 27, 27, 31, 30),
  test1_score = c(18.9, 19.5, 19.6, 12.9, 11.1, 7.3, 4.3, 3.9, 2.5, 1.6),
  test2_score = c(9.1, 9.1, 9.2, 11.1, 13.9, 14.5, 19.2, 19.3, 19.1, 18.8),
  stringsAsFactors = FALSE)

您可以使用这样的额外颜色格式制作漂亮的表格:

library(formattable)
formattable(df, list(
  age = color_tile("white", "orange"),
  test1_score = color_bar("pink", 0.2),
  test2_score = color_bar("pink", 0.2)
))

看起来像这样:

我想要做的是现在过滤这个表,这样我只保留前n行 - 这里n = 3.不这样做的方法是进行典型的子集化,因为颜色标度现在仅应用于数据子集的最小值/最大值,而不是原始数据.即

formattable(df[1:3,], list(
  age = color_tile("white", "orange"),
  test1_score = color_bar("pink", 0.2),
  test2_score = color_bar("pink", 0.2)
))

这看起来像这样:

这显然重新调整了颜色.

看着str对象:

str(
formattable(df, list(
  age = color_tile("white", "orange"),
  test1_score = color_bar("pink", 0.2),
  test2_score = color_bar("pink", 0.2)
)) 
)

Classes ‘formattable’ and 'data.frame': 10 obs. of  5 variables:
 $ id         : int  1 2 3 4 5 6 7 8 9 10
 $ name       : chr  "Bob" "Ashley" "James" "David" ...
 $ age        : num  48 47 40 28 29 29 27 27 31 30
 $ test1_score: num  18.9 19.5 19.6 12.9 11.1 7.3 4.3 3.9 2.5 1.6
 $ test2_score: num  9.1 9.1 9.2 11.1 13.9 14.5 19.2 19.3 19.1 18.8
 - attr(*, "formattable")=List of 4
  ..$ formatter: chr "format_table"
  ..$ format   :List of 1
  .. ..$ :List of 3
  .. .. ..$ age        :function (x)  
  .. .. ..$ test1_score:function (x)  
  .. .. ..$ test2_score:function (x)  
  ..$ preproc  : NULL
  ..$ postproc : NULL

由于结构包含其他元素,因此无法仅对生成的对象进行过滤/子集化.

是否有任何方法只输出前n行​​,如果使用整个表/数据帧,它们将具有它们将具有的色标？

Answer 1

从数据帧的子集重新缩放是设计的特征.如果您确实需要避免重新缩放,可以尝试当前可用的解决方法:

subset_df <- function(m) {
  formattable(df[m, ], list(
    age = x ~ color_tile("white", "orange")(df$age)[m],
    test1_score = x ~ color_bar("pink", 0.2)(df$test1_score)[m],
    test2_score = x ~ color_bar("pink", 0.2)(df$test2_score)[m]
  ))
}

subset_df(1:5)
subset_df(c(1,3,5,9))
subset_df(df$age <= mean(df$age))

它基本上强制每列的格式化程序函数应用于固定数据,并使用相同的子集过滤生成的格式化值.