Syntax error How to divide matrix values by row variance in R?

How to divide matrix values by row variance in R?

To divide matrix row values by row variance in R, we can follow the below steps −

  • First of all, create a matrix.
  • Then, use apply function to divide the matrix row values by row variance.

Create the matrix

Let's create a matrix as shown below −

 Live Demo

M<-matrix(sample(1:20,75,replace=TRUE),ncol=3)
M

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

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

Divide the matrix row values by row variance

Using apply function to divide the row values of M by row variance −

 Live Demo

M<-matrix(sample(1:20,75,replace=TRUE),ncol=3)
M_new<-t(apply(M,1, function(x) x/var(x)))
M_new

Output

         [,1]       [,2]       [,3]
[1,] 0.26530612 0.04081633 0.30612245
[2,] 0.43548387 0.38709677 0.14516129
[3,] 0.57692308 1.03846154 0.69230769
[4,] 0.29081633 0.07653061 0.29081633
[5,] 0.32432432 0.35135135 0.05405405
[6,] 2.53846154 1.84615385 1.61538462
[7,] 0.04972376 0.29834254 0.11602210
[8,] 0.13761468 0.46788991 0.33027523
[9,] 0.26582278 0.64556962 0.53164557
[10,] 0.05263158 0.23684211 0.02631579
[11,] 0.32374101 0.04316547 0.10791367
[12,] 0.02325581 0.32558140 0.20930233
[13,] 0.04633205 0.22007722 0.02316602
[14,] 0.49484536 0.40206186 0.15463918
[15,] 2.81250000 2.81250000 3.56250000
[16,] 0.32432432 0.02702703 0.05405405
[17,] 0.32967033 0.52747253 0.16483516
[18,] 0.09045226 0.06030151 0.28643216
[19,] 2.68421053 1.89473684 2.36842105
[20,] 2.00000000 3.00000000 3.00000000
[21,] 0.19402985 0.02985075 0.26865672
[22,] 0.22959184 0.01530612 0.22959184
[23,] 0.02325581 0.32558140 0.20930233
[24,] 1.61538462 0.92307692 1.84615385
[25,] 0.19917012 0.01244813 0.21161826
Updated on: 2021-08-14T08:36:21+05:30

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