计划为每个Label计算按地区划分的平均值，并将其保存到新数据框。由于我有一个庞大的数据集，我需要一个循环 - 任何帮助都将非常感激。
structure(list(Label = structure(c(1L, 2L, 1L, 1L, 2L, 2L, 2L,
1L), .Label = c("a", "b"), class = "factor"), Region = structure(c(3L,
1L, 1L, 1L, 1L, 2L, 2L, 3L), .Label = c("EUR", "GLB", "UK"), class = "factor"),
Value = c(-6, 17, 26, -37, 44, -22, 15, 12)), .Names = c("Label",
"Region", "Value"), row.names = c(NA, -8L), class = "data.frame")