订购数据框时的奇怪行为

Question

我有以下数据框,我想按第五列("距离")排序.当我尝试`

df.order <- df[order(df[, 5]), ]

我总是收到以下错误消息.

Error in order(df[, 5]) : unimplemented type 'list' in 'orderVector1'`

我不知道为什么R将我的数据框视为列表.运行is.data.frame(df)回报TRUE.我不得不承认is.list(df)也会回来TRUE.是否可以强制我的数据框只是一个数据框而不是一个列表？谢谢你的帮助.

structure(list(ID = list(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), 
               Latitude = list(50.7368, 50.7368, 50.7368, 50.7369, 50.7369, 50.737, 50.737, 50.7371, 50.7371, 50.7371), 
               Longitude = list(6.0873, 6.0873, 6.0873, 6.0872, 6.0872, 6.0872, 6.0872, 6.0872, 6.0872, 6.0872), 
               Elevation = list(269.26, 268.99, 268.73, 268.69, 268.14, 267.87, 267.61, 267.31, 267.21, 267.02), 
               Distance = list(119.4396, 119.4396, 119.4396, 121.199, 121.199, 117.5658, 117.5658, 114.9003, 114.9003, 114.9003), 
               RxPower = list(-52.6695443922406, -52.269130891243, -52.9735258244422, -52.2116571930007, -51.7784534281727, -52.7703448813654, -51.6558862949081, -52.2892907635308, -51.8322993596551, -52.4971436682333)), 
          .Names = c("ID", "Latitude", "Longitude", "Elevation", "Distance", "RxPower"),
          row.names = c(NA, 10L), class = "data.frame")

Answer 1

您的数据框包含列表,而不是矢量.您可以使用as.data.frame和将此数据框转换为"经典"格式unlist:

df2 <- as.data.frame(lapply(df, unlist))

现在,新数据框可以按预期方式排序:

df2[order(df2[, 5]), ]