How to divide each value in an R data frame by 100?

We sometimes need to perform mathematical operations on all values in the data set. One such operation could be dividing each value by 100.

For example, if we have a data frame called df then we can divide each value in df by 100 by using the below command −

df[,1:ncol(df)]/100

Example

Following snippet creates a sample data frame −

x1<-rpois(20,25) x2<-rpois(20,21) x3<-rpois(20,37) x4<-rpois(20,32) df1<-data.frame(x1,x2,x3,x4) df1

Output

The following dataframe is created −

   x1  x2  x3  x4 1  34  17  33  42 2  29  22  28  39 3  28  24  35  26 4  17  21  34  26 5  28  15  38  40 6  20  15  37  30 7  24  18  33  35 8  29  25  43  24 9  37  21  37  34 10 15  16  37  28 11 27  26  38  28 12 33  24  42  31 13 21  23  33  30 14 17  19  39  31 15 26  17  46  21 16 22  29  49  32 17 28  24  40  37 18 21  12  38  34 19 22  19  41  33 20 28  10  36  27

Now to divide each value in df1 by 100, add the following code to the above snippet −

df1[,1:ncol(df1)]/100 

The following dataframe is created −

    x1     x2    x3    x4 1  0.34  0.17  0.33  0.42 2  0.29  0.22  0.28  0.39 3  0.28  0.24  0.35  0.26 4  0.17  0.21  0.34  0.26 5  0.28  0.15  0.38  0.40 6  0.20  0.15  0.37  0.30 7  0.24  0.18  0.33  0.35 8  0.29  0.25  0.43  0.24 9  0.37  0.21  0.37  0.34 10 0.15  0.16  0.37  0.28 11 0.27  0.26  0.38  0.28 12 0.33  0.24  0.42  0.31 13 0.21  0.23  0.33  0.30 14 0.17  0.19  0.39  0.31 15 0.26  0.17  0.46  0.21 16 0.22  0.29  0.49  0.32 17 0.28  0.24  0.40  0.37 18 0.21  0.12  0.38  0.34 19 0.22  0.19  0.41  0.33 20 0.28  0.10  0.36  0.27

Example

Following snippet creates a sample data frame −

y1<-sample(100:200,20) y2<-sample(100:200,20) y3<-sample(100:200,20) df2<-data.frame(y1,y2,y3) df2

Output

The following dataframe is created −

    y1   y2   y3 1  154  132  114 2  199  106  190 3  161  196  141 4  127  184  103 5  177  120  183 6  113  194  137 7  128  181  142 8  192  135  164 9  100  139  127 10 175  114  200 11 184  147  172 12 187  164  132 13 162  173  184 14 130  161  102 15 157  102  150 16 134  110  157 17 140  192  139 18 119  195  111 19 150  148  187 20 110  188  146

Now, to divide each value in df2 by 100, add the following code to the above snippet −

df2[,1:ncol(df2)]/100 

The following dataframe is created −

    y1    y2    y3 1  1.54  1.32  1.14 2  1.99  1.06  1.90 3  1.61  1.96  1.41 4  1.27  1.84  1.03 5  1.77  1.20  1.83 6  1.13  1.94  1.37 7  1.28  1.81  1.42 8  1.92  1.35  1.64 9  1.00  1.39  1.27 10 1.75  1.14  2.00 11 1.84  1.47  1.72 12 1.87  1.64  1.32 13 1.62  1.73  1.84 14 1.30  1.61  1.02 15 1.57  1.02  1.50 16 1.34  1.10  1.57 17 1.40  1.92  1.39 18 1.19  1.95  1.11 19 1.50  1.48  1.87 20 1.10  1.88  1.46