如何基于行分组执行成对分割

Question

我有一个数据框,通过以下方式:

df <- structure(list(celltype = structure(c(1L, 1L, 2L, 2L, 3L, 3L,
4L, 4L, 5L, 5L, 6L, 6L, 7L, 7L, 8L, 8L, 9L, 9L, 10L, 10L), .Label = c("Bcells",
"DendriticCells", "Macrophages", "Monocytes", "NKCells", "Neutrophils",
"StemCells", "StromalCells", "abTcells", "gdTCells"), class = "factor"),
    sample = c("SP ID control", "SP ID treated", "SP ID control",
    "SP ID treated", "SP ID control", "SP ID treated", "SP ID control",
    "SP ID treated", "SP ID control", "SP ID treated", "SP ID control",
    "SP ID treated", "SP ID control", "SP ID treated", "SP ID control",
    "SP ID treated", "SP ID control", "SP ID treated", "SP ID control",
    "SP ID treated"), `mean(score)` = c(0.160953535029424, 0.155743474395545,
    0.104788051104575, 0.125247035158472, -0.159665650045289,
    -0.134662049979712, 0.196249441751866, 0.212256889027029,
    0.0532668251890109, 0.0738264693971133, 0.151828478029596,
    0.159941552142933, -0.14128323638966, -0.120556640790534,
    0.196518649474078, 0.185264282171863, 0.0654641151966543,
    0.0837989059507186, 0.145111577618456, 0.145448549866796)), .Names = c("celltype",
"sample", "mean(score)"), row.names = c(7L, 8L, 17L, 18L, 27L,
28L, 37L, 38L, 47L, 48L, 57L, 58L, 67L, 68L, 77L, 78L, 87L, 88L,
97L, 98L), class = "data.frame")

它看起来像这样:

> df
         celltype        sample mean(score)
7          Bcells SP ID control  0.16095354
8          Bcells SP ID treated  0.15574347
17 DendriticCells SP ID control  0.10478805
18 DendriticCells SP ID treated  0.12524704
27    Macrophages SP ID control -0.15966565
28    Macrophages SP ID treated -0.13466205
37      Monocytes SP ID control  0.19624944
38      Monocytes SP ID treated  0.21225689
47        NKCells SP ID control  0.05326683
48        NKCells SP ID treated  0.07382647
57    Neutrophils SP ID control  0.15182848
58    Neutrophils SP ID treated  0.15994155
67      StemCells SP ID control -0.14128324
68      StemCells SP ID treated -0.12055664
77   StromalCells SP ID control  0.19651865
78   StromalCells SP ID treated  0.18526428
87       abTcells SP ID control  0.06546412
88       abTcells SP ID treated  0.08379891
97       gdTCells SP ID control  0.14511158
98       gdTCells SP ID treated  0.14544855

我想要做的是为基于分数的分裂treated和control内样本cell type分组.

以下Excel图像说明了该示例.我们追求最正确的专栏.例如在Bcells(0.155/0.161 = 0.967)中.

在一天结束时,我想得到看起来像这样的df:

celltype            sample          Pairwise division
Bcells              SP ID treated   0.967630031
DendriticCells      SP ID treated   1.195241574
Macrophages         SP ID treated   0.843400255
Monocytes           SP ID treated   1.081566841
NKCells             SP ID treated   1.385974647
Neutrophils         SP ID treated   1.053435786
StemCells           SP ID treated   0.853297563
StromalCells        SP ID treated   0.942731303
abTcells            SP ID treated   1.280073915
gdTCells            SP ID treated   1.002322158

我怎样才能在R中实现这一目标？

Answer 1

如果您的数据已订购并完全配对:

pair_index <- 1:(dim(df)[1]/2)*2
df[pair_index,'pairwise-division'] <- df[pair_index,3] / df[pair_index-1,3]
df[pair_index,c(1,2,4)]