Replace Values Based on Condition in R

In this article, we will examine various methods to replace values based on conditions in the R Programming Language.

How to replace values based on condition

R language offers a method to replace values based on conditions efficiently. By using these methods provided by R, it is possible to replace values based on condition easily. Some of the methods to replace values based on condition are:

Method 1: Replacing value based on a Single condition

This method is used to replace value or data based on a single condition efficiently. In the below example, we created the data frame and replaced the value based on a single Condition.

# Creating data frame
df <- data.frame(
      name=c("A", "B", "C", "D", "E"),
      age=c(24,21,23,25,24),
      id_no=c(4203,4438,4477,4486,4576))
print("The data frame is")
print(df)

 df$age[df$age == 24] = 55
 print("Replacing value based on single condition")
print(df)

Output:

[1] "The data frame is"
  name age    id_no
1     A      24      4203
2    B      21      4438
3    C     23      4477
4    D     25      4486
5    E      24      4576

[1] "Replacing value based on single condition"
   name age   id_no
1    A      55      4203
2    B      21      4438
3    C     23      4477
4    D     25     4486
5    E     55     4576

In the below example, we created the data frame and replaced the value based on single Condition.

# Creating data frame
df <- data.frame(
      A=c(10:14),
      B=c("a","b","c","d","a"),
      C=c("abc","def","mno","pqr","abc"))
print("The data frame is")
print(df)

 df$C[df$C== "abc"] = "gfg"
 print("Replacing value based on single condition")
print(df)

Output:

[1] "The data frame is"
    A   B   C
1  10  a  abc
2  11  b  def
3  12 c  mno
4  13 d  pqr
5  14 a  abc

[1] "Replacing value based on single condition"
    A   B   C
1  10  a  gfg
2  11  b  def
3  12 c  mno
4  13 d  pqr
5  14 a  gfg

Method 2: Replacing value based on Multiple Conditions

This method is used to replace value or data based on a multiple Conditions efficiently. In the below example, we created the data frame and replaced the value based on multiple Conditions .

nos=c(50,20,30,40,50)
r_no=c(105,102,103,104,105)
emp_id=c(2302:2306)

# Creating data frame
df <- data.frame(nos, r_no, emp_id)
print("The data frame is")
print(df)

df$nos[df$nos == 50 & df$r_no == 105] <- 600
print("Replacing value based on multiple conditions")
print(df)

Output:

[1] "The data frame is"
   nos   r_no   emp_id
1   50    105        2302
2   20   102       2303
3   30   103       2304
4   40   104      2305
5   50   105      2306

[1] "Replacing value based on multiple conditions"
    nos    r_no   emp_id
1  600     105     2302
2   20      102     2303
3   30      103     2304
4   40      104    2305
5  600    105     2306

In the below example, we created the data frame and replaced the value based on multiple Conditions.

# Creating data frame
df = data.frame(   
     name=c("ramya", "kumari" ,"raghu", "sravya", "kumari"),
     sex=c("F", "F", "M", "F","F"),
     state=c("Andhra pradesh","odhisa","delhi","kerla","odhisa"))

print("The data frame is")
print(df)

df$state[df$state == "odhisa" & df$name =="kumari" ] = "Hyderabad"
print("Replacing value based on multiple conditions")
print(df)

Output:

[1] "The data frame is"
     name    sex          state
1   ramya    F        Andhra pradesh
2  kumari    F         odhisa
3   raghu    M          delhi
4  sravya    F          kerla
5  kumari    F         odhisa

[1] "Replacing value based on multiple conditions"
     name     sex          state
1    ramya    F         Andhra pradesh
2   kumari   F        Hyderabad
3   raghu     M          delhi
4   sravya    F          kerla
5   kumari    F        Hyderabad

Conclusion

In conclusion, we learned about how to replace values based on condition by using R. R language offers versatile tools while performing replacing the data efficiently.