Question

我需要将聚合（平均值）的输出转换为矩阵外部样式。

data(mtcars)
aggregate(disp ~ cyl + gear, data = mtcars, FUN = mean )

  cyl gear     disp
  4    3 120.1000
  6    3 241.5000
  8    3 357.6167
  4    4 102.6250
  6    4 163.8000
  4    5 107.7000
  6    5 145.0000
  8    5 326.0000

我需要的是将disp的方法放入一个带有齿轮列和圆柱形

的矩阵中

喜欢这个

    3   4   5
4 120 102 107
6 241 163 145
8 357 NA 326

你有什么建议我怎么做这个转变？

有没有办法使用这个功能

outer

？

structure(list(mpg = c(21, 21, 22.8, 21.4, 18.7, 18.1, 14.3, 
24.4, 22.8, 19.2, 17.8, 16.4, 17.3, 15.2, 10.4, 10.4, 14.7, 32.4, 
30.4, 33.9, 21.5, 15.5, 15.2, 13.3, 19.2, 27.3, 26, 30.4, 15.8, 
19.7, 15, 21.4), cyl = c(6, 6, 4, 6, 8, 6, 8, 4, 4, 6, 6, 8, 
8, 8, 8, 8, 8, 4, 4, 4, 4, 8, 8, 8, 8, 4, 4, 4, 8, 6, 8, 4), 
disp = c(160, 160, 108, 258, 360, 225, 360, 146.7, 140.8, 
167.6, 167.6, 275.8, 275.8, 275.8, 472, 460, 440, 78.7, 75.7, 
71.1, 120.1, 318, 304, 350, 400, 79, 120.3, 95.1, 351, 145, 
301, 121), hp = c(110, 110, 93, 110, 175, 105, 245, 62, 95, 
123, 123, 180, 180, 180, 205, 215, 230, 66, 52, 65, 97, 150, 
150, 245, 175, 66, 91, 113, 264, 175, 335, 109), drat = c(3.9, 
3.9, 3.85, 3.08, 3.15, 2.76, 3.21, 3.69, 3.92, 3.92, 3.92, 
3.07, 3.07, 3.07, 2.93, 3, 3.23, 4.08, 4.93, 4.22, 3.7, 2.76, 
3.15, 3.73, 3.08, 4.08, 4.43, 3.77, 4.22, 3.62, 3.54, 4.11
), wt = c(2.62, 2.875, 2.32, 3.215, 3.44, 3.46, 3.57, 3.19, 
3.15, 3.44, 3.44, 4.07, 3.73, 3.78, 5.25, 5.424, 5.345, 2.2, 
1.615, 1.835, 2.465, 3.52, 3.435, 3.84, 3.845, 1.935, 2.14, 
1.513, 3.17, 2.77, 3.57, 2.78), qsec = c(16.46, 17.02, 18.61, 
19.44, 17.02, 20.22, 15.84, 20, 22.9, 18.3, 18.9, 17.4, 17.6, 
18, 17.98, 17.82, 17.42, 19.47, 18.52, 19.9, 20.01, 16.87, 
17.3, 15.41, 17.05, 18.9, 16.7, 16.9, 14.5, 15.5, 14.6, 18.6
), vs = c(0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 
0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1), am = c(1, 
1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 
0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1), gear = c(4, 4, 4, 3, 
3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, 4, 3, 3, 3, 
3, 3, 4, 5, 5, 5, 5, 5, 4), carb = c(4, 4, 1, 1, 2, 1, 4, 
2, 2, 4, 4, 3, 3, 3, 4, 4, 4, 1, 2, 1, 1, 2, 2, 4, 2, 1, 
2, 2, 4, 6, 8, 2)), .Names = c("mpg", "cyl", "disp", "hp", 
"drat", "wt", "qsec", "vs", "am", "gear", "carb"), row.names = c("Mazda RX4", 
"Mazda RX4 Wag", "Datsun 710", "Hornet 4 Drive", "Hornet Sportabout", 
"Valiant", "Duster 360", "Merc 240D", "Merc 230", "Merc 280", 
"Merc 280C", "Merc 450SE", "Merc 450SL", "Merc 450SLC", "Cadillac Fleetwood", 
"Lincoln Continental", "Chrysler Imperial", "Fiat 128", "Honda Civic", 
"Toyota Corolla", "Toyota Corona", "Dodge Challenger", "AMC Javelin", 
"Camaro Z28", "Pontiac Firebird", "Fiat X1-9", "Porsche 914-2", 
"Lotus Europa", "Ford Pantera L", "Ferrari Dino", "Maserati Bora", 
"Volvo 142E"), class = "data.frame")

Answer 1

您可以尝试tapply

with(mtcars, tapply(disp, list(cyl, gear), FUN=mean))
#       3       4     5
#4 120.1000 102.625 107.7
#6 241.5000 163.800 145.0
#8 357.6167      NA 326.0

如果您希望reshape输出aggregate，我们可以使用acast中的reshape2

d1 <- aggregate(disp ~ cyl + gear, data = mtcars, FUN = mean )
acast(d1, cyl~gear, value.var='disp')

R中的矩阵变换 - 从聚合输出到外类矩阵

1 个答案: