將R data.frame轉換為熱圖概念的特定json文件

Question

我在R中有以下數據框：

df <- data.frame(RowNames <- c("FirstCol","SecondCol","ThirdCol","FourthCol"),
                               FirstCol <- c(0.4,0.5,0.1,0.2),
                               SecondCol <- c(0.8,0.6,0.4,0.1),
                               ThirdCol <- c(0.7,0.1,0.2,0.6),
                               FourthCol <- c(0.5,0.3,0.1,0.9))
names(df) <- c("RowNames", "FirstCol", "SecondCol", "ThirdCol", "FourthCol")

我喜歡將此數據幀轉換為非常具體的json文件，以進一步提供熱圖繪制概念：

# desired output
{
  "x": [ "FirstCol", "SecondCol", "ThirdCol", "FourthCol" ],
  "y": [ "FourthCol", "ThirdCol", "SecondCol", "FirstCol" ],
  "z": [
    [ 0.2, 0.1, 0.6, 0.9 ],
    [ 0.1, 0.4, 0.2, 0.1 ],
    [ 0.5, 0.6, 0.1, 0.3 ],
    [ 0.4, 0.8, 0.7, 0.5 ]]
}

有沒有具體的方法，如何以最簡單的方式做到這一點？ 我真的不知道我應該從哪里開始。 非常感謝您提前提供的任何幫助。

Answer 1

我們可以通過在命名list放置names和數據（從最后一行反向到第一行）來使用jsonlite的toJSON 。

library(jsonlite)
toJSON(list(x=names(df)[-1], y=rev(names(df)[-1]),  
         z=`dimnames<-`(as.matrix(df[nrow(df):1,-1]), NULL)))
{
 "x":["FirstCol","SecondCol","ThirdCol","FourthCol"],
 "y":["FourthCol","ThirdCol","SecondCol","FirstCol"],
 "z":[[0.2,0.1,0.6,0.9],
      [0.1,0.4,0.2,0.1],
      [0.5,0.6,0.1,0.3],
      [0.4,0.8,0.7,0.5]]
 }