How to find the percent of zeros in each row of a data.table object in R?

To find the percent of zeros in each row of a data.table object in R, we can follow the below steps −

• First of all, create a data.table object.

• Then, use rowSums function along with ncol function to find the percent of zeros in each row of the data.table object.

Example

Create the data.table object

Let’s create a data.table object as shown below −

library(data.table) v1<-sample(0:2,25,replace=TRUE) v2<-sample(0:2,25,replace=TRUE) v3<-sample(0:2,25,replace=TRUE) v4<-sample(0:2,25,replace=TRUE) v5<-sample(0:2,25,replace=TRUE) DT<-data.table(v1,v2,v3,v4,v5) DT

Output

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

 v1 v2 v3 v4 v5 1: 2 1 1 1 1 2: 1 2 2 2 1 3: 1 2 1 0 1 4: 1 1 0 2 0 5: 0 1 0 0 2 6: 0 0 0 2 1 7: 0 0 1 0 0 8: 1 2 1 1 2 9: 1 2 2 1 0 10: 1 1 1 2 0 11: 1 2 0 0 0 12: 2 2 0 0 0 13: 2 2 2 2 2 14: 2 2 1 1 0 15: 2 1 0 2 2 16: 1 1 2 0 2 17: 0 0 2 1 1 18: 2 1 2 1 1 19: 2 1 2 2 1 20: 1 0 2 0 2 21: 0 0 2 2 2 22: 2 0 1 2 0 23: 0 2 2 1 0 24: 2 1 2 1 1 25: 2 2 2 0 2 v1 v2 v3 v4 v5

Find the percent of zeros in each row

Using rowSums function along with ncol function to find the percent of zeros in each row of the data.table object DT −

library(data.table) v1<-sample(0:2,25,replace=TRUE) v2<-sample(0:2,25,replace=TRUE) v3<-sample(0:2,25,replace=TRUE) v4<-sample(0:2,25,replace=TRUE) v5<-sample(0:2,25,replace=TRUE) DT<-data.table(v1,v2,v3,v4,v5) DT$Percent_0s<-(rowSums(DT==0)/ncol(DT))*100 DT

Output

 v1 v2 v3 v4 v5 Percent_0s 1: 2 1 1 1 1 0 2: 1 2 2 2 1 0 3: 1 2 1 0 1 20 4: 1 1 0 2 0 40 5: 0 1 0 0 2 60 6: 0 0 0 2 1 60 7: 0 0 1 0 0 80 8: 1 2 1 1 2 0 9: 1 2 2 1 0 20 10: 1 1 1 2 0 20 11: 1 2 0 0 0 60 12: 2 2 0 0 0 60 13: 2 2 2 2 2 0 14: 2 2 1 1 0 20 15: 2 1 0 2 2 20 16: 1 1 2 0 2 20 17: 0 0 2 1 1 40 18: 2 1 2 1 1 0 19: 2 1 2 2 1 0 20: 1 0 2 0 2 40 21: 0 0 2 2 2 40 22: 2 0 1 2 0 40 23: 0 2 2 1 0 40 24: 2 1 2 1 1 0 25: 2 2 2 0 2 20 v1 v2 v3 v4 v5 Percent_0s