How to divide the row values by row mean in data.table object in R?

R Programming Server Side Programming Programming

To divide the row values by row mean in R’s data.table object, we can follow the below steps −

First of all, create a data.table object.
Then, use apply function to divide the data.table object row values by row mean.

Create the data frame

library(data.table)
x<-sample(1:50,25)
y<-sample(1:50,25)
z<-sample(1:50,25)
DT<-data.table(x,y,z)
DT

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

     x y  z
1:  26 34 16
2:  2  23 40
3:  23 9  37
4:  24 14 22
5:  4  20 33
6:  35 38 47
7:  21 3  10
8:  34 41 13
9:  42 33 35
10: 15 7  4
11: 18 1  23
12: 45 4  49
13: 11 8  19
14: 50 49  5
15: 13 39  9
16: 12 21 46
17: 20 29 42
18: 28 32 38
19: 25 47 32
20: 32 22 20
21: 46 45 43
22: 6 15  31
23: 22 48 29
24: 30 5  17
25: 27 46 44
    x  y  z

Divide the data.table object row values by row mean

Using apply function to divide the row values of DT by row mean −

library(data.table)
x<-sample(1:50,25)
y<-sample(1:50,25)
z<-sample(1:50,25)
DT<-data.table(x,y,z)
DT_new<-t(apply(DT,1, function(x) x/mean(x)))
DT_new

Output

         x          y          z
[1,] 1.02631579 1.34210526 0.6315789
[2,] 0.09230769 1.06153846 1.8461538
[3,] 1.00000000 0.39130435 1.6086957
[4,] 1.20000000 0.70000000 1.1000000
[5,] 0.21052632 1.05263158 1.7368421
[6,] 0.87500000 0.95000000 1.1750000
[7,] 1.85294118 0.26470588 0.8823529
[8,] 1.15909091 1.39772727 0.4431818
[9,] 1.14545455 0.90000000 0.9545455
[10,] 1.73076923 0.80769231 0.4615385
[11,] 1.28571429 0.07142857 1.6428571
[12,] 1.37755102 0.12244898 1.5000000
[13,] 0.86842105 0.63157895 1.5000000
[14,] 1.44230769 1.41346154 0.1442308
[15,] 0.63934426 1.91803279 0.4426230
[16,] 0.45569620 0.79746835 1.7468354
[17,] 0.65934066 0.95604396 1.3846154
[18,] 0.85714286 0.97959184 1.1632653
[19,] 0.72115385 1.35576923 0.9230769
[20,] 1.29729730 0.89189189 0.8108108
[21,] 1.02985075 1.00746269 0.9626866
[22,] 0.34615385 0.86538462 1.7884615
[23,] 0.66666667 1.45454545 0.8787879
[24,] 1.73076923 0.28846154 0.9807692
[25,] 0.69230769 1.17948718 1.1282051

Nizamuddin Siddiqui

Published on 06-Aug-2021 11:57:09

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