How to find the mean of corresponding elements of multiple matrices in R?

Question

How to find the mean of corresponding elements of multiple matrices in R?

R ProgrammingServer Side ProgrammingProgramming

---

---

If the elements of multiple matrices represent the same type of characteristic then we might want to find the mean of those elements. For example, if we have matrices M1, M2, M3, and M4 stored in a list and the first element represent the rate of a particular thing, say Rate of decay of rusty iron during rainy season, then we might want to find the mean of first element of matrix M1, M2, M3, and M4. This mean can be found by using Reduce function.

Example

Consider the below matrices and their list −

 Live Demo

> M1<-matrix(1:25,nrow=5)
> M1

Output

   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11   16  21
[2,] 2    7    12   17   22
[3,] 3    8    13  18    23
[4,] 4    9    14  19    24
[5,] 5    10   15  20    25

> M2<-matrix(1:25,nrow=5)
> M3<-matrix(1:25,nrow=5)
> M4<-matrix(1:25,nrow=5)
> List_M<-list(M1,M2,M3,M4)
> List_M

Output

[[1]]
   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11    16 21
[2,] 2    7    12    17 22
[3,] 3    8    13    18 23
[4,] 4    9    14    19 24
[5,] 5    10    15    20 25
[[2]]
   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11    16 21
[2,] 2    7    12    17 22
[3,] 3    8    13    18 23
[4,] 4    9    14    19 24
[5,] 5    10    15    20 25
[[3]]
   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11    16 21
[2,] 2    7    12    17 22
[3,] 3    8    13    18 23
[4,] 4    9    14    19 24
[5,] 5    10    15    20 25
[[4]]
   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11    16 21
[2,] 2    7    12    17 22
[3,] 3    8    13    18 23
[4,] 4    9    14    19 24
[5,] 5    10    15    20 25

Finding the mean of corresponding elements in each matrix −

> Reduce("+",List_M)/length(List_M)

Output

   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11   16 21
[2,] 2    7    12   17 22
[3,] 3    8    13   18 23
[4,] 4    9    14   19 24
[5,] 5    10    15  20 25

Let’s have a look at another example −

Example

 Live Demo

> M1<-matrix(sample(1:10,16,replace=TRUE),ncol=4)
> M1

Output

   [,1] [,2] [,3] [,4]
[1,] 6    7    3    2
[2,] 10   10  3    1
[3,] 7    6    6    5
[4,] 6    7    3    10

Example

 Live Demo

> M2<-matrix(sample(1:10,16,replace=TRUE),ncol=4)
> M2

Output

   [,1] [,2] [,3] [,4]
[1,] 9    2    5    7
[2,] 9    4    4    3
[3,] 4    6    8    6
[4,] 3    7    7    5

Example

 Live Demo

> M3<-matrix(sample(1:10,16,replace=TRUE),ncol=4)
> M3

Output

   [,1] [,2] [,3] [,4]
[1,] 2    10    3    8
[2,] 8    10    2    8
[3,] 9    6    2    6
[4,] 8    8    6    9

Example

 Live Demo

> M4<-matrix(sample(1:10,16,replace=TRUE),ncol=4)
> M4

Output

   [,1] [,2] [,3] [,4]
[1,] 8    3    8    5
[2,] 7    5    5    7
[3,] 1    9    1    4
[4,] 10   1    8    9

Example

> List_new<-list(M1,M2,M3,M4)
> List_new

Output

[[1]]
   [,1] [,2] [,3] [,4]
[1,] 6    7    3    2
[2,] 10   10  3    1
[3,] 7    6    6    5
[4,] 6    7    3   10
[[2]]
   [,1] [,2] [,3] [,4]
[1,] 9    2    5    7
[2,] 9    4    4    3
[3,] 4    6    8    6
[4,] 3    7    7    5
[[3]]
   [,1] [,2] [,3] [,4]
[1,] 2    10    3    8
[2,] 8    10    2    8
[3,] 9    6    2    6
[4,] 8    8    6    9
[[4]]
   [,1] [,2] [,3] [,4]
[1,] 8    3    8    5
[2,] 7    5    5    7
[3,] 1    9    1    4
[4,] 10    1   8    9

> Reduce("+",List_new)/length(List_new)

Output

   [,1]    [,2]    [,3]    [,4]
[1,] 6.25    5.50    4.75  5.50
[2,] 8.50    7.25    3.50   4.75
[3,] 5.25    6.75    4.25    5.25
[4,] 6.75    5.75    6.00    8.25

Nizamuddin Siddiqui

Published on 04-Sep-2020 11:22:13

Previous Page Print Page

Next Page  

Advertisements