How to find the length of columns for missing values in R?

The length of columns for missing values means the number of missing values in the data frame. This can be easily done with the help of colSums function where we will find the total number of NA values with is.na. For example, if we have a data frame called df that contains some missing values then the length of columns for missing values can be found by using the command colSums(is.na(df)).

Example1

Consider the below data frame −

Live Demo

> x1<-sample(c(1,NA),20,replace=TRUE) > x2<-sample(c(5,NA),20,replace=TRUE) > x3<-sample(c(2,NA),20,replace=TRUE) > x4<-sample(c(2,NA),20,replace=TRUE) > df1<-data.frame(x1,x2,x3,x4) > df1

Output

   x1 x2 x3 x4 1  NA NA  2  2 2  NA NA NA  2 3   1 NA  2 NA 4  NA  5 NA NA 5   1  5 NA NA 6  NA  5 NA  2 7   1 NA NA  2 8   1  5 NA NA 9  NA NA  2 NA 10  1  5 NA NA 11 NA NA NA NA 12 NA NA  2  2 13  1 NA NA  2 14  1 NA NA  2 15 NA NA NA NA 16  1 NA NA NA 17  1  5 NA NA 18 NA NA  2 NA 19  1 NA NA NA 20  1 NA  2  2

Finding the length of columns for missing values in df1 −

> colSums(is.na(df1))

Output

x1 x2 x3 x4 9 14 14 12

Example2

Live Demo

> y1<-sample(c(101,NA),20,replace=TRUE) > y2<-sample(c(325,NA),20,replace=TRUE) > y3<-sample(c(250,NA),20,replace=TRUE) > df2<-data.frame(y1,y2,y3) > df2

Output

    y1  y2  y3 1  101 325  NA 2   NA  NA  NA 3  101  NA  NA 4  101 325 250 5   NA  NA  NA 6  101 325 250 7  101 325  NA 8   NA 325 250 9  101 325 250 10  NA 325  NA 11 101 325 250 12  NA  NA 250 13 101  NA  NA 14  NA 325  NA 15  NA 325  NA 16  NA  NA  NA 17  NA  NA  NA 18 101 325 250 19 101  NA  NA 20  NA 325 250

Finding the length of columns for missing values in df2 −

> colSums(is.na(df2))

Output

y1 y2 y3 10 8 12