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Asked: 2026-06-08T10:20:16+00:00

I have a list where each element is a 5*5 matrix. Eg [[1]] V1

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I have a list where each element is a 5*5 matrix. Eg

[[1]]   
           V1          V2          V3          V4          V5      
      [1,]   0.000000   46.973700   21.453500  338.547000   10.401600 
      [2,]  43.020500    0.000000  130.652000  840.526000   56.363700 
      [3,]  12.605600  173.238000    0.000000  642.075000   19.628100 
      [4,] 217.946000  626.368000  481.329000    0.000000  642.341000 
      [5,] 217.946000  626.368000  481.329000    0.000000  642.341000 
[[2]]   
           V1          V2          V3          V4          V5      
      [1,]   0.000000   47.973700   21.453500  338.547000   10.401600 
      [2,]  143.020500    0.000000  130.652000  840.526000   56.363700 
      [3,]  312.605600  17.238000    0.000000  642.075000   19.628100 
      [4,]  17.946000  126.368000  481.329000    0.000000  642.341000
      [5,] 217.946000  626.368000  481.329000    0.000000  642.341000  
...

How can I use an apply-like function to sum matrix [1] to [n], and return a 5*5 matrix as a result (each element is a sum of the corresponding elements in each of the matrix in the list) ?

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1 Answer

  1. Editorial Team

    Use Reduce. 

    ## dummy data

.list <- list(matrix(1:25, ncol = 5), matrix(1:25, ncol = 5))

Reduce('+', .list)
##       [,1] [,2] [,3] [,4] [,5]
## [1,]    2   12   22   32   42
## [2,]    4   14   24   34   44
## [3,]    6   16   26   36   46
## [4,]    8   18   28   38   48
## [5,]   10   20   30   40   50
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