我正在尝试使用'R'将相当大的数据集（530行，211列）子集成为46行，21行中的21行，16行中的1行和2行中的1行的2个子集。我没有多次复制代码，而是想为此做一个循环。此外，在子集化时，我想删除子集中的前3列。
对于子集，我使用此代码：
Dataveg2018A <- subset(DatasetMerg, Year == "2018" & Block == "A",
Select= 4:7)
由于我不想为每个子集创建不同的代码，我想使用循环，但我无法弄清楚如何编写它。
我有三个不同的“年份”类别，并且每年我都会阻止A：J。我希望每年以块为单位对整个数据集进行子集化，并为此使用循环。
下面我发布了一小部分数据集的代码（使用函数dput）。请原谅我仍然把它变得繁琐，但我无法弄清楚如何压缩它。
因此，我需要一个代码，每年为每个Block循环上面的子集命令，从而产生总共25个子集。在下面的压缩数据集中，它应该产生3个子集（1个2018块A，一个2008块A和一个2001块A.
我希望我足够清楚。
structure(list(Year = structure(c(`18A01` = 3L, `18A02` = 3L,
`18A03` = 3L, `18A04` = 3L, `18A05` = 3L, `18A06` = 3L, `18A07` = 3L,
`18A08` = 3L, `18A09` = 3L, `18A10` = 3L, `18A11` = 3L, `18A12` = 3L,
`18A13` = 3L, `18A14` = 3L, `18A15` = 3L, `18A16` = 3L, `18A17` = 3L,
`18A18` = 3L, `18A19` = 3L, `18A20` = 3L, `08A01` = 2L, `08A02` = 2L,
`08A03` = 2L, `08A04` = 2L, `08A05` = 2L, `08A06` = 2L, `08A07` = 2L,
`08A08` = 2L, `08A09` = 2L, `08A10` = 2L, `08A11` = 2L, `08A12` = 2L,
`08A13` = 2L, `08A14` = 2L, `08A15` = 2L, `08A16` = 2L, `08A17` = 2L,
`08A18` = 2L, `08A19` = 2L, `08A20` = 2L, `01A01` = 1L, `01A02` = 1L,
`01A03` = 1L, `01A04` = 1L, `01A05` = 1L, `01A06` = 1L, `01A07` = 1L,
`01A08` = 1L, `01A09` = 1L, `01A10` = 1L, `01A11` = 1L, `01A12` = 1L,
`01A13` = 1L, `01A14` = 1L, `01A15` = 1L, `01A16` = 1L, `01A17` = 1L,
`01A18` = 1L, `01A19` = 1L, `01A20` = 1L), .Label = c("2001",
"2008", "2018"), class = "factor"), Block = structure(c(`18A01` = 1L,
`18A02` = 1L, `18A03` = 1L, `18A04` = 1L, `18A05` = 1L, `18A06` = 1L,
`18A07` = 1L, `18A08` = 1L, `18A09` = 1L, `18A10` = 1L, `18A11` = 1L,
`18A12` = 1L, `18A13` = 1L, `18A14` = 1L, `18A15` = 1L, `18A16` = 1L,
`18A17` = 1L, `18A18` = 1L, `18A19` = 1L, `18A20` = 1L, `08A01` = 1L,
`08A02` = 1L, `08A03` = 1L, `08A04` = 1L, `08A05` = 1L, `08A06` = 1L,
`08A07` = 1L, `08A08` = 1L, `08A09` = 1L, `08A10` = 1L, `08A11` = 1L,
`08A12` = 1L, `08A13` = 1L, `08A14` = 1L, `08A15` = 1L, `08A16` = 1L,
`08A17` = 1L, `08A18` = 1L, `08A19` = 1L, `08A20` = 1L, `01A01` = 1L,
`01A02` = 1L, `01A03` = 1L, `01A04` = 1L, `01A05` = 1L, `01A06` = 1L,
`01A07` = 1L, `01A08` = 1L, `01A09` = 1L, `01A10` = 1L, `01A11` = 1L,
`01A12` = 1L, `01A13` = 1L, `01A14` = 1L, `01A15` = 1L, `01A16` = 1L,
`01A17` = 1L, `01A18` = 1L, `01A19` = 1L, `01A20` = 1L), .Label = c("A",
"B", "C", "D", "E", "F", "G", "H", "I", "J", "X"), class = "factor"),
Plot = structure(c(`18A01` = 1L, `18A02` = 2L, `18A03` = 3L,
`18A04` = 4L, `18A05` = 5L, `18A06` = 6L, `18A07` = 7L, `18A08` = 8L,
`18A09` = 9L, `18A10` = 10L, `18A11` = 11L, `18A12` = 12L,
`18A13` = 13L, `18A14` = 14L, `18A15` = 15L, `18A16` = 16L,
`18A17` = 17L, `18A18` = 18L, `18A19` = 19L, `18A20` = 20L,
`08A01` = 1L, `08A02` = 2L, `08A03` = 3L, `08A04` = 4L, `08A05` = 5L,
`08A06` = 6L, `08A07` = 7L, `08A08` = 8L, `08A09` = 9L, `08A10` = 10L,
`08A11` = 11L, `08A12` = 12L, `08A13` = 13L, `08A14` = 14L,
`08A15` = 15L, `08A16` = 16L, `08A17` = 17L, `08A18` = 18L,
`08A19` = 19L, `08A20` = 20L, `01A01` = 1L, `01A02` = 2L,
`01A03` = 3L, `01A04` = 4L, `01A05` = 5L, `01A06` = 6L, `01A07` = 7L,
`01A08` = 8L, `01A09` = 9L, `01A10` = 10L, `01A11` = 11L,
`01A12` = 12L, `01A13` = 13L, `01A14` = 14L, `01A15` = 15L,
`01A16` = 16L, `01A17` = 17L, `01A18` = 18L, `01A19` = 19L,
`01A20` = 20L), .Label = c(" 1", " 2", " 3", " 4", " 5",
" 6", " 7", " 8", " 9", "10", "11", "12", "13", "14", "15",
"16", "17", "18", "19", "20", "21", "22", "23", "24", "25",
"26", "27", "28", "29", "30", "31", "32", "33", "34", "35",
"36", "37", "38", "39", "40", "41", "42", "43", "44", "45",
"46"), class = "factor"), Agrimonia.eupatoria = structure(c(`18A01` = 3L,
`18A02` = 2L, `18A03` = 1L, `18A04` = 1L, `18A05` = 1L, `18A06` = 1L,
`18A07` = 1L, `18A08` = 1L, `18A09` = 1L, `18A10` = 1L, `18A11` = 1L,
`18A12` = 1L, `18A13` = 1L, `18A14` = 1L, `18A15` = 1L, `18A16` = 1L,
`18A17` = 1L, `18A18` = 1L, `18A19` = 1L, `18A20` = 1L, `08A01` = 1L,
`08A02` = 1L, `08A03` = 1L, `08A04` = 1L, `08A05` = 1L, `08A06` = 1L,
`08A07` = 1L, `08A08` = 1L, `08A09` = 1L, `08A10` = 1L, `08A11` = 1L,
`08A12` = 1L, `08A13` = 1L, `08A14` = 1L, `08A15` = 1L, `08A16` = 1L,
`08A17` = 1L, `08A18` = 1L, `08A19` = 1L, `08A20` = 1L, `01A01` = 3L,
`01A02` = 1L, `01A03` = 1L, `01A04` = 1L, `01A05` = 1L, `01A06` = 1L,
`01A07` = 1L, `01A08` = 1L, `01A09` = 1L, `01A10` = 1L, `01A11` = 1L,
`01A12` = 1L, `01A13` = 1L, `01A14` = 1L, `01A15` = 1L, `01A16` = 1L,
`01A17` = 1L, `01A18` = 1L, `01A19` = 1L, `01A20` = 1L), .Label = c("0",
"1", "2", "6"), class = "factor"), Agrostis.capillaris = structure(c(`18A01`
= 1L,
`18A02` = 1L, `18A03` = 1L, `18A04` = 1L, `18A05` = 1L, `18A06` = 1L,
`18A07` = 1L, `18A08` = 1L, `18A09` = 1L, `18A10` = 1L, `18A11` = 1L,
`18A12` = 1L, `18A13` = 1L, `18A14` = 1L, `18A15` = 1L, `18A16` = 1L,
`18A17` = 1L, `18A18` = 1L, `18A19` = 1L, `18A20` = 1L, `08A01` = 1L,
`08A02` = 1L, `08A03` = 1L, `08A04` = 1L, `08A05` = 1L, `08A06` = 1L,
`08A07` = 1L, `08A08` = 1L, `08A09` = 1L, `08A10` = 1L, `08A11` = 1L,
`08A12` = 1L, `08A13` = 1L, `08A14` = 1L, `08A15` = 1L, `08A16` = 1L,
`08A17` = 1L, `08A18` = 1L, `08A19` = 1L, `08A20` = 1L, `01A01` = 1L,
`01A02` = 1L, `01A03` = 1L, `01A04` = 1L, `01A05` = 1L, `01A06` = 1L,
`01A07` = 1L, `01A08` = 1L, `01A09` = 1L, `01A10` = 1L, `01A11` = 1L,
`01A12` = 1L, `01A13` = 1L, `01A14` = 1L, `01A15` = 1L, `01A16` = 1L,
`01A17` = 1L, `01A18` = 1L, `01A19` = 1L, `01A20` = 1L), .Label = c("0",
"2", "3", "4", "6"), class = "factor"), Agrostis.gigantea =
structure(c(`18A01` = 1L,
`18A02` = 1L, `18A03` = 1L, `18A04` = 1L, `18A05` = 1L, `18A06` = 1L,
`18A07` = 1L, `18A08` = 1L, `18A09` = 1L, `18A10` = 1L, `18A11` = 2L,
`18A12` = 3L, `18A13` = 2L, `18A14` = 1L, `18A15` = 3L, `18A16` = 3L,
`18A17` = 4L, `18A18` = 3L, `18A19` = 1L, `18A20` = 1L, `08A01` = 1L,
`08A02` = 1L, `08A03` = 1L, `08A04` = 1L, `08A05` = 1L, `08A06` = 1L,
`08A07` = 1L, `08A08` = 1L, `08A09` = 1L, `08A10` = 1L, `08A11` = 1L,
`08A12` = 1L, `08A13` = 1L, `08A14` = 1L, `08A15` = 1L, `08A16` = 1L,
`08A17` = 1L, `08A18` = 1L, `08A19` = 1L, `08A20` = 1L, `01A01` = 1L,
`01A02` = 1L, `01A03` = 1L, `01A04` = 1L, `01A05` = 1L, `01A06` = 1L,
`01A07` = 1L, `01A08` = 1L, `01A09` = 1L, `01A10` = 1L, `01A11` = 1L,
`01A12` = 1L, `01A13` = 1L, `01A14` = 1L, `01A15` = 1L, `01A16` = 1L,
`01A17` = 1L, `01A18` = 1L, `01A19` = 1L, `01A20` = 1L), .Label = c("0",
"2", "3", "4", "6"), class = "factor"), Agrostis.stolonifera =
structure(c(`18A01` = 5L,
`18A02` = 1L, `18A03` = 1L, `18A04` = 1L, `18A05` = 1L, `18A06` = 1L,
`18A07` = 1L, `18A08` = 1L, `18A09` = 1L, `18A10` = 1L, `18A11` = 1L,
`18A12` = 1L, `18A13` = 1L, `18A14` = 1L, `18A15` = 1L, `18A16` = 1L,
`18A17` = 1L, `18A18` = 1L, `18A19` = 1L, `18A20` = 1L, `08A01` = 5L,
`08A02` = 1L, `08A03` = 1L, `08A04` = 1L, `08A05` = 1L, `08A06` = 1L,
`08A07` = 1L, `08A08` = 1L, `08A09` = 1L, `08A10` = 1L, `08A11` = 1L,
`08A12` = 1L, `08A13` = 5L, `08A14` = 1L, `08A15` = 1L, `08A16` = 1L,
`08A17` = 1L, `08A18` = 1L, `08A19` = 1L, `08A20` = 1L, `01A01` = 1L,
`01A02` = 1L, `01A03` = 1L, `01A04` = 1L, `01A05` = 1L, `01A06` = 1L,
`01A07` = 1L, `01A08` = 1L, `01A09` = 1L, `01A10` = 1L, `01A11` = 1L,
`01A12` = 1L, `01A13` = 1L, `01A14` = 1L, `01A15` = 1L, `01A16` = 1L,
`01A17` = 1L, `01A18` = 1L, `01A19` = 1L, `01A20` = 1L), .Label = c("0",
"1", "18", "2", "3", "38", "4", "6", "68", "8"), class = "factor")),
row.names = c("18A01",
"18A02", "18A03", "18A04", "18A05", "18A06", "18A07", "18A08",
"18A09", "18A10", "18A11", "18A12", "18A13", "18A14", "18A15",
"18A16", "18A17", "18A18", "18A19", "18A20", "08A01", "08A02",
"08A03", "08A04", "08A05", "08A06", "08A07", "08A08", "08A09",
"08A10", "08A11", "08A12", "08A13", "08A14", "08A15", "08A16",
"08A17", "08A18", "08A19", "08A20", "01A01", "01A02", "01A03",
"01A04", "01A05", "01A06", "01A07", "01A08", "01A09", "01A10",
"01A11", "01A12", "01A13", "01A14", "01A15", "01A16", "01A17",
"01A18", "01A19", "01A20"), class = "data.frame")
这样的事情可能会让你得到你想要的东西。它将运行每年的子集并阻塞，并将结果存储在命名列表中。
lst.subsets <- list()
subset.iterator <- 0
# Get all possible years from dataframe
years <- unique(DatasetMerg$Year)
for(y in years){
# Get all possible blocks for the current year
blocks <- unique(DatasetMerg[DatasetMerg$Year == y, "Block"])
for(b in blocks){
subset.iterator <- subset.iterator + 1
lst.subsets[[subset.iterator]] <- subset(DatasetMerg,
Year == y & Block == b,
select = c(4:7))
names(lst.subsets)[[subset.iterator]] <- paste0('Dataveg', y, b)
}
}