我有几个计数变量矩阵,我们可以表示如下:
P <- matrix(c(1, 2 ,0, 2, 5, 1, 0, 6, 1), nrow = 3)
Q <- matrix(c(1, 0, 0, 2, 3, 1, 0, 4, 1), nrow = 3)
R <- matrix(c(2, 1, 1, 5, 6, 4, 0, 4, 1), nrow = 3)
S <- matrix(c(9, 7, 5, 4, 7, 3, 2, 6, 3), nrow = 3)
我想创建将这些矩阵相加的所有组合。例如。 P+Q、P+R、P+S、Q+R、Q+S、R+S、P+Q+R、P+R+S、P+Q+S、Q+R+S...
我知道如何手动运行它:
PQ <-P+Q
> PQ
[,1] [,2] [,3]
[1,] 2 4 0
[2,] 2 8 10
[3,] 0 2 2
PQR <- P+Q+R
> PQR
[,1] [,2] [,3]
[1,] 4 9 0
[2,] 3 14 14
[3,] 1 6 3
但是我的真实数据集有 9 个矩阵,这意味着 501 个组合,这需要很长时间才能写出来。
所以我尝试了这个:
# generate all possible combinations of the matrices
combs <- combn(list(P, Q, R, S), 2, simplify = FALSE)
print(combs)
# sum the matrices in each combination
sums <- lapply(combs, function(x) Reduce("+", x))
# print the result
print(sums)
一方面,似乎确实可以进行所有组合。但它不允许我知道哪个组合是哪个。
如何将所有矩阵添加在一起并确保名称反映了正在添加的矩阵,以便我稍后可以调用它们?
1) 创建一个命名列表,首先计算总和,然后添加名称。
L <- list(P = P, Q = Q, R = R, S = S)
Sums2 <- combn(L, 2, Reduce, f = `+`, simplify = FALSE)
names(Sums2) <- combn(names(L), 2, paste, collapse = "+")
Sums3 <- combn(L, 2, Reduce, f = `+`, simplify = FALSE)
names(Sums3) <- combn(names(L), 3, paste, collapse = "+")
Sums <- c(Sums2, Sums3)
2) 另一种可能性是使用列表推导式。
L
是从上面看的。 gen.named.list
的第一个参数定义名称,第二个参数定义值。
library(listcompr)
Sums2 <- gen.named.list("{i}+{j}", L[[i]] + L[[j]],
i = names(L), j = names(L), i < j)
Sums3 <- gen.named.list("{i}+{j}+{k}", L[[i]] + L[[j]] + L[[k]],
i = names(L), j = names(L), k = names(L), i < j, j < k)
Sums <- c(Sums2, Sums3)
您可以尝试以下代码
lst <- list(P = P, Q = Q, R = R, S = S)
out <- do.call(
c,
lapply(
2:length(lst),
\(k) unlist(
combn(lst,
k, \(...)
setNames(
list(Reduce(`+`, ...)),
paste0(names(...), collapse = "")
),
simplify = FALSE
),
recursive = FALSE
)
)
)
其中
out
给出
$PQ
[,1] [,2] [,3]
[1,] 2 4 0
[2,] 2 8 10
[3,] 0 2 2
$PR
[,1] [,2] [,3]
[1,] 3 7 0
[2,] 3 11 10
[3,] 1 5 2
$PS
[,1] [,2] [,3]
[1,] 10 6 2
[2,] 9 12 12
[3,] 5 4 4
$QR
[,1] [,2] [,3]
[1,] 3 7 0
[2,] 1 9 8
[3,] 1 5 2
$QS
[,1] [,2] [,3]
[1,] 10 6 2
[2,] 7 10 10
[3,] 5 4 4
$RS
[,1] [,2] [,3]
[1,] 11 9 2
[2,] 8 13 10
[3,] 6 7 4
$PQR
[,1] [,2] [,3]
[1,] 4 9 0
[2,] 3 14 14
[3,] 1 6 3
$PQS
[,1] [,2] [,3]
[1,] 11 8 2
[2,] 9 15 16
[3,] 5 5 5
$PRS
[,1] [,2] [,3]
[1,] 12 11 2
[2,] 10 18 16
[3,] 6 8 5
$QRS
[,1] [,2] [,3]
[1,] 12 11 2
[2,] 8 16 14
[3,] 6 8 5
$PQRS
[,1] [,2] [,3]
[1,] 13 13 2
[2,] 10 21 20
[3,] 6 9 6
如果要创建如
PQ
名称所示的变量PQR
、out
等变量,可以进一步使用list2env
list2env(out, envir = .GlobalEnv)