# How to convert a correlation matrix into a logical matrix based on correlation coefficient in R?

To convert a correlation matrix into a logical matrix based on correlation coefficient in R, we can follow the below steps −

• First of all, create a matrix.

• Then, find the correlation matrix.

• After that, convert the correlation matrix into logical matrix based on coefficient value using greater than or less than sign.

## Example 1

Let’s create a matrix as shown below −

Live Demo

M1<-matrix(sample(1:100,100),ncol=4)
M1

On executing, the above script generates the below output(this output will vary on your system due to randomization) −

## Output

   [,1] [,2] [,3] [,4]
[1,] 91 22 61 37
[2,] 33 89 49 9
[3,] 71 6 36 13
[4,] 51 18 57 90
[5,] 41 23 4 54
[6,] 30 64 77 43
[7,] 67 12 65 7
[8,] 80 47 97 2
[9,] 34 32 21 79
[10,] 24 73 17 25
[11,] 66 38 45 58
[12,] 52 53 92 63
[13,] 31 74 76 100
[14,] 95 69 82 35
[15,] 27 60 98 59
[16,] 50 44 55 16
[17,] 29 88 11 81
[18,] 28 14 99 72
[19,] 1 68 15 78
[20,] 5 46 86 84
[21,] 70 10 19 93
[22,] 3 94 87 20
[23,] 56 39 75 62
[24,] 26 40 8 42
[25,] 85 83 96 48

## Find the correlation matrix

Using cor function to find the correlation matrix −

Live Demo

M1<-matrix(sample(1:100,100),ncol=4)
Cor_M1<-cor(M1)
Cor_M1

## Output

        [,1]       [,2]       [,3]       [,4]
[1,] 1.0000000 -0.35856139 0.1834276 -0.29261479
[2,] -0.3585614 1.00000000 0.1613665 -0.08473756
[3,] 0.1834276 0.16136649 1.0000000 -0.12695909
[4,] -0.2926148 -0.08473756 -0.1269591 1.00000000

## Convert the correlation matrix into logical matrix based on correlation coefficient

Using correlation coefficient value 0.15 to convert Cor_M1 into logical matrix with TRUE where correlation coefficient is greater than 0.15 −

Live Demo

M1<-matrix(sample(1:100,100),ncol=4)
Cor_M1<-cor(M1)
Cor_M1_Above_0.15 <- Cor_M1>0.15
Cor_M1_Above_0.15

## Output

    [,1]  [,2] [,3] [,4]
[1,] TRUE FALSE TRUE FALSE
[2,] FALSE TRUE TRUE FALSE
[3,] TRUE TRUE TRUE FALSE
[4,] FALSE FALSE FALSE TRUE

## Example2

Let’s create a matrix as shown below −

Live Demo

M2<-matrix(round(rnorm(100),1),ncol=4)
M2

On executing, the above script generates the below output(this output will vary on your system due to randomization) −

## Output

       [,1] [,2] [,3] [,4]
[1,]   0.4 -0.6 -1.0 -0.6
[2,]   1.2 -0.4  0.4 1.2
[3,]   -0.2 1.0 -0.5 0.9
[4,]   0.0 -1.7 -1.6 -2.1
[5,]  -0.4 -1.6  0.3 0.7
[6,]  -0.4 -1.4  1.7 0.0
[7,]   1.1 -0.3  0.3 0.6
[8,]   0.2 -0.2 -0.4 -0.3
[9,]   0.2  0.9 -0.7 0.2
[10,]  0.6 -0.7  0.1 -0.1
[11,] -1.8 -0.7  0.3 0.3
[12,]  0.4 -0.6 -1.5 0.8
[13,] -0.1  0.7  0.4 0.1
[14,]  0.6 -0.5 -0.2 -1.2
[15,] -0.2  0.1 -0.6 0.1
[16,]  0.6 -0.3  0.8 -1.5
[17,] -0.4  0.6 -0.8 -0.3
[18,] -0.5 -2.1 -2.5 -1.2
[19,] -0.8  0.5  1.6 0.1
[20,]  0.2 -2.3  1.2 1.1
[21,] -0.2  0.4 -0.2 -1.5
[22,]  0.3 -1.2 -0.2 -2.1
[23,]  0.5 -0.6  1.1 -0.2
[24,] -0.4  0.9  0.7 -0.8
[25,] -0.1  0.6  0.2 -0.2

## Find the correlation matrix

Using cor function to find the correlation matrix −

Live Demo

M2<-matrix(round(rnorm(100),1),ncol=4)
Cor_M2<-cor(M2)
Cor_M2

## Output

         [,1]       [,2]       [,3]       [,4]
[1,] 1.00000000 -0.0548232 -0.02367749 0.02923548
[2,] -0.05482320 1.0000000 0.10940827 0.11996196
[3,] -0.02367749 0.1094083 1.00000000 0.29432660
[4,] 0.02923548 0.1199620 0.29432660 1.00000000

## Convert the correlation matrix into logical matrix based on correlation coefficient

Using correlation coefficient value 0.25 to convert Cor_M2 into logical matrix with TRUE where correlation coefficient is greater than 0.25 −

Live Demo

M2<-matrix(round(rnorm(100),1),ncol=4)
Cor_M2<-cor(M2)
Cor_M2_Above_0.25 <- Cor_M2>0.25
Cor_M2_Above_0.25

## Output

     [,1] [,2]  [,3]  [,4]
[1,] TRUE FALSE FALSE FALSE
[2,] FALSE TRUE FALSE FALSE
[3,] FALSE FALSE TRUE TRUE
[4,] FALSE FALSE TRUE TRUE

Updated on: 11-Aug-2021

158 Views 