How to convert a character data frame to numeric data frame in R?

Sometimes numerical values are recorded as character values and we need to convert them to numeric type before starting our analysis. This is also possible for a whole data frame in R. Therefore, we can use sapply function to convert the columns of the data frame to numeric type and save the output in a data frame by reading it with as.data.frame.

Example1

Consider the below data frame −

 Live Demo

x<−sample(c("1","2","3"),20,replace=TRUE)
df1<−data.frame(x)
df1

Output

   x
1  2
2  2
3  2
4  1
5  2
6  3
7  1
8  2
9  2
10 2
11 1
12 1
13 2
14 2
15 1
16 1
17 3
18 2
19 3
20 1

Checking the structure of df1 −

Example

str(df1)

Output

'data.frame': 20 obs. of 1 variable:
$ x: chr "2" "2" "2" "1" ...

Converting the data type of columns of df1 to numeric data type −

Example

df1<−as.data.frame(sapply(df1,as.numeric))
str(df1)

Output

'data.frame': 20 obs. of 1 variable:
$ x: num 2 2 2 1 2 3 1 2 2 2 ...

Example2

 Live Demo

y1<−sample(c("254","324","220","301"),20,replace=TRUE)
df2<−data.frame(y1)
df2

Output

   y1
1  324
2  254
3  220
4  254
5  220
6  220
7  324
8  254
9  324
10 220
11 324
12 324
13 301
14 324
15 220
16 301
17 301
18 324
19 301
20 254

Example

str(df2)

Output

'data.frame': 20 obs. of 1 variable:
$ y1: chr "324" "254" "220" "254" ...

Example

df2<−as.data.frame(sapply(df2,as.numeric))
str(df2)

Output

'data.frame': 20 obs. of 1 variable:
$ y1: num 324 254 220 254 220 220 324 254 324 220 ...