Subset Data Frames Using Logical Conditions In R

In this article, we will explore various methods of Subset data frames using logical conditions using the R Programming Language.

How to Subset data frames using logical conditions

R language offers various methods to subset data frames using logical conditions. By using these methods provided by R, it is possible to subset a data frame. Some of the methods to subset data frames using logical conditions are:

Subset data frame with ==

This method is used to perform subsetting on a data frame. In the below example, we created a data frame and performed subsetting by using logical conditions.

#creating data frame
df <- data.frame( a1 = c(3, 7, 1, 8, 5,8),                    
                   a2 = letters[3:8],
                   batch = c("b0","b1","b2","b1","b3","b1"))
print(df)

print("After subsetting the data frame")
df[df$batch == "b1", ] 

Output:

 a1 a2 batch
1  3  c    b0
2  7  d    b1
3  1  e    b2
4  8  f    b1
5  5  g    b3
6  8  h    b1

[1] "After subsetting the data frame"
  a1 a2 batch
2  7  d    b1
4  8  f    b1
6  8  h    b1

Subset data frame with %in%

This method is used to perform subsetting on a data frame. In this below example, we created a data frame and performed subsetting by using logical condition.

# creating data Frame
df <- data.frame(
  name = c("a","b","c","d","e"),
  id = c(15, 30, 45, 60, 75),
  batch=c("a0","b1","b2","b1","c1")
)
print(df)

print("After subsetting the data frame ")

res=df[df$batch %in% c("b1", "c1"), ] 
print(res)

Output:

 name id batch
1    a 15    a0
2    b 30    b1
3    c 45    b2
4    d 60    b1
5    e 75    c1

[1] "After subsetting the data frame "
  name id batch
2    b 30    b1
4    d 60    b1
5    e 75    c1

Subset data frame with !=

This method is used to perform subsetting on a data frame. In this below example, we created a data frame and performed subsetting by using logical condition.

#creating data frame
df <- data.frame( a1 = c(3, 7, 1, 8, 5,8),                  
                   a2 = letters[3:8],
                   batch = c("b0","b1","b2","b1","b3","b1"))
print(df)

print("After subsetting the data frame")
df[df$batch != "b1", ]                                   

Output:

 a1 a2 batch
1  3  c    b0
2  7  d    b1
3  1  e    b2
4  8  f    b1
5  5  g    b3
6  8  h    b1

[1] "After subsetting the data frame"
  a1 a2 batch
1  3  c    b0
3  1  e    b2
5  5  g    b3

Subsetting data frame by using Square Brackets [ ]:

This method is used to perform subsetting on a data frame. In this below example, we created a data frame and performed subsetting by using logical condition

# creating data Frame
df <- data.frame(
  name = c("a","b","c","d","e"),
  id = c(15, 30, 45, 60, 75),
  batch=c("a0","b1","b2","a2","c1")
)
print(df)

print("After subsetting the data frame ")
subset_df <- df[df$id > 30, ]
print(subset_df)

Output:

name id batch
1    a 15    a0
2    b 30    b1
3    c 45    b2
4    d 60    a2
5    e 75    c1

[1] "After subsetting the data frame "
  name id batch
3    c 45    b2
4    d 60    a2
5    e 75    c1

Subsetting data frame by using subset() Function

This method is used to perform subsetting on a data frame. In this below example, we created a data frame and performed subsetting by using logical condition.

# creating data Frame
df <- data.frame(
  name = c("a","b","c","d","e"),
  id = c(15, 30, 45, 60, 75),
  batch=c("a0","b1","b2","a2","c1")
)
print(df)

print("After subsetting the data frame ")
subset_df <- subset(df, id > 45 )
print(subset_df)

Output:

  name id batch
1    a 15    a0
2    b 30    b1
3    c 45    b2
4    d 60    a2
5    e 75    c1

[1] "After subsetting the data frame "
  name id batch
4    d 60    a2
5    e 75    c1

Conclusion

In conclusion, we learned about how to perform subsetting by using logical conditions. R language offers versatile tools while performing subsetting on various data sets.