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r - 根据列值对行进行分组并在 R 中保留具有最小值的行

问题描述

在下面的数据集中，我想首先检查该列的哪些行U并且D具有相同的值。然后，对于这样一组具有U和作为相同值的行，我想保留对 columns和V具有最小值的行。对于我拥有的数据，这三个将始终具有与 where和match的行组中的同一行的最小值。MeanMinMaxUV

我尝试group()了函数，但它没有像我想要的那样产生输出。请提出任何有效的方法。

输入数据

data <- structure(list(A = c(0.18, 0.18, 0.18, 0.18, 0.18, 0.18, 0.18, 
0.18, NA, NA, NA, NA, NA, NA), B = c(0.33, 0.33, 0.33, 0.33, 
0.33, 0.33, 0.33, 0.33, 1, 2, 2, 2, 3, 4), C = structure(c(1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "Yes", class = "factor"), 
    U = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 
    2L, 2L, 2L), .Label = c("ABC-001", "PQR-001"), class = "factor"), 
    D = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 
    2L, 2L, 2L), .Label = c("ABC", "PQR"), class = "factor"), 
    E = structure(c(1L, 2L, 3L, 4L, 4L, 5L, 5L, 6L, 1L, 1L, 2L, 
    2L, 3L, 3L), .Label = c("A", "B", "C", "D", "E", "F"), class = "factor"), 
    F = c(22000014L, 22000031L, 22000033L, 22000025L, 22000028L, 
    22000020L, 22000021L, 22000015L, 11100076L, 11200076L, 11100077L, 
    11200077L, 11100078L, 11200078L), G = c(0, 0, 0, 0, 0, 0, 
    0, 0, -0.1, -0.1, -0.1, -0.1, 0.2, 0.2), H = c(100, 100, 
    100, 100, 100, 100, 100, 100, 1.2, 1.2, 1.2, 1.2, 0.9, 0.9
    ), I = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 
    2L, 2L, 2L, 2L), .Label = c("us", "V"), class = "factor"), 
    Mean = c(38.72, 37.52111111, 38.44166667, 39.23666667, 39.35888889, 
    38.96, 38.95333333, 38.41777778, 0.691707061, 0.691554561, 
    0.691516833, 0.691423506, 0.763736, 0.764015761), Min = c(34.05, 
    33.25, 33.31, 35.14, 33.91, 33.78, 33.78, 33.75, 0.6911166, 
    0.6908743, 0.6908813, 0.6907286, 0.7609318, 0.7616949), Max = c(43.83, 
    42.12, 43.57, 44.03, 44.88, 44.03, 44.02, 43.52, 0.692533, 
    0.6922278, 0.6923681, 0.6919283, 0.7674736, 0.7668633)), class = "data.frame", row.names = c(NA, 
-14L))

预期输出

output <- read.table(header = TRUE, text = "    A   B   C   U   D   E   F   G   H   I   Mean    Min Max
+ 0.18  0.33    Yes ABC-001 ABC B   22000031    0   100 us  37.52111111 33.25   42.12
+ NA    2   Yes PQR-001 PQR B   11200077    -0.1    1.2 V   0.691423506 0.6907286   0.6919283
+ ")

标签： rdataframe

解决方案

您可以与order基地duplicated核对R 

data = data[order(data$Mean),]
output = data[!duplicated(data[c("U","D")]),]
output
      A    B   C       U   D E        F    G     H  I       Mean        Min        Max
12   NA 2.00 Yes PQR-001 PQR B 11200077 -0.1   1.2  V  0.6914235  0.6907286  0.6919283
2  0.18 0.33 Yes ABC-001 ABC B 22000031  0.0 100.0 us 37.5211111 33.2500000 42.1200000

如果你想dplyr 

library(dplyr)
data %>% group_by(U, D) %>% slice(which.min(Mean))

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