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列表中矩阵的滚动和

sum matrix list r

1

John L. Godlee · 技术社区 · 7 年前

我有一个相同大小的矩阵列表:

a <- matrix(data = c(1,2,3,4,5,6,7,8,9), ncol = 3, nrow = 3)

b <- matrix(data = c(9,8,7,6,5,4,3,2,1), ncol = 3, nrow = 3)

c <- matrix(data = c(1,2,3,4,5,6,7,8,9), ncol = 3, nrow = 3)

d <- matrix(data = seq(from = 1, to = 9, by = 1), ncol = 3, nrow = 3)

e <- matrix(data = seq(from = 10, to = 90, by = 10), ncol = 3, nrow = 3)

f <- matrix(data = seq(from = 9, to = 1, by = -1), ncol = 3, nrow = 3)


test_list <- list(a, b, c, d, e, f)

如何对三个矩阵的每一组求和,使输出为两个矩阵,第一个是 a , b 和 c ( output_1 d e 和 f ( output_2

output_1 <- structure(c(11, 12, 13, 14, 15, 16, 17, 18, 19), .Dim = c(3L, 
3L)) 

output_2 <- structure(c(3L, 6L, 9L, 12L, 15L, 18L, 21L, 24L, 27L), .Dim = c(3L, 
3L))

5 回复 | 直到 7 年前

1

4

zack 7 年前

library(purrr)
map(split(test_list, ceiling(seq_along(test_list)/3)), ~reduce(.x , `+`))

$`1`
     [,1] [,2] [,3]
[1,]   11   14   17
[2,]   12   15   18
[3,]   13   16   19

$`2`
     [,1] [,2] [,3]
[1,]    3   12   21
[2,]    6   15   24
[3,]    9   18   27

信用 to this answer 对于整洁的分裂代码。

2

M-- 7 年前

data.table :

data.table::rbindlist(lapply(test_list, function(x) as.data.frame(x)))[, as.list(colSums(.SD)), 
                                     by = gl(ceiling(length(test_list)*nrow(test_list[[1]])/3), 
                                     3, length(test_list)*nrow(test_list[[1]]))]

3

2

IRTFM 7 年前

43秒前@iod评论了我的想法。我把它作为一个与 map - reduce -扎克回答的逻辑是:

lapply( split( test_list, cumsum( rep( c(T,F,F), 2))), function(x){ Reduce( "+", x)})
$`1`
     [,1] [,2] [,3]
[1,]   11   14   17
[2,]   12   15   18
[3,]   13   16   19

$`2`
     [,1] [,2] [,3]
[1,]    3   12   21
[2,]    6   15   24
[3,]    9   18   27

lapply-split 而Reduce实际上是伪装的循环。

cumsum 生成一个数值向量。使用的Masoud gl . zack 习惯于 ceiling(seq_along(test_list)/3) 并有礼貌地相信了它的灵感。

4

1

iod 7 年前

转换为数组并 apply rowSums :

test_array<-array(c(a,b,c,d,e,f),c(3,3,6))
apply(test_array[,1:3,1:3],2,rowSums)

     [,1] [,2] [,3]
[1,]   11   14   17
[2,]   12   15   18
[3,]   13   16   19

apply(test_array[,1:3,4:6],2,rowSums)

     [,1] [,2] [,3]
[1,]    3   12   21
[2,]    6   15   24
[3,]    9   18   27

5

1

r.user.05apr 7 年前

或:

Matrix_Number <- 6

res <- vector("list", Matrix_Number / 3)
for (i in (1:(Matrix_Number/3))) {
  res[[i]] <- test_list[[(i-1)*3 + 1]] + test_list[[(i-1)*3 + 2]] + test_list[[(i-1)*3 + 3]]
}
res