Replace string in dataframe with different column values

Question

I have dataframe that looks like:

 Tester Type    Subject Type    Time        1     2     3
 TType1         SType1          Day 1       11    2     1         
 TType1         SType2          Day 1       3     2     13
 TType1         SType1          Day 2       2     3     15
 TType2         SType3          Day 2       1     4     3
 TType3         SType3          Day 2       2     3     4
 TType1         SType1          Day 1       7     2     2
 TType2         SType1          Day 2       2     6     7

I'm trying to find all SType 1 in Subject Type column and replace it with Values in Tester Type. So, my output would look like:

 Tester Type    Subject Type    Time        1     2     3
 TType1         TType1          Day 1       11    2     1         
 TType1         SType2          Day 1       3     2     13
 TType1         TType1          Day 2       2     3     15
 TType2         SType3          Day 2       1     4     3
 TType3         SType3          Day 2       2     3     4
 TType1         TType1          Day 1       7     2     2
 TType2         TType2          Day 2       2     6     7

What did you try so far? There is a lot of resources on this site to perform such operation. — user3710546
– user3710546, Commented Dec 9, 2015 at 5:27
Possible duplicate of Replace value in column with corresponding value from another column in same dataframe — Alex
– Alex, Commented Dec 9, 2015 at 5:32

akrun · Accepted Answer · 2015-12-10 02:51:49Z

2

We can use ifelse

ifelse(df$SubjectType == "SType1", df$TesterType, df$SubjectType)
# [1] "TType1" "SType2" "TType1" "SType3" "SType3" "TType1" "TType2"

Assuming df as your data frame.

edited Dec 10, 2015 at 2:51

akrun

891k38 gold badges590 silver badges700 bronze badges

answered Dec 9, 2015 at 5:38

Ronak Shah

391k20 gold badges173 silver badges237 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

akrun · Accepted Answer · 2015-12-09 06:01:36Z

2

We can use data.table. We convert the 'data.frame' to 'data.table' (setDT(df1)), using the logical condition as 'i', we assign (:=) the 'SubjectType' that corresponds to the rows in 'i' as 'TesterType'.

library(data.table)
setDT(df1)[SubjectType=='SType1', SubjectType := TesterType]
df1
#   TesterType SubjectType  Time X1 X2 X3
#1:     TType1      TType1 Day 1 11  2  1
#2:     TType1      SType2 Day 1  3  2 13
#3:     TType1      TType1 Day 2  2  3 15
#4:     TType2      SType3 Day 2  1  4  3
#5:     TType3      SType3 Day 2  2  3  4
#6:     TType1      TType1 Day 1  7  2  2
#7:     TType2      TType2 Day 2  2  6  7

edited Dec 9, 2015 at 6:01

answered Dec 9, 2015 at 5:56

akrun

891k38 gold badges590 silver badges700 bronze badges

Collectives™ on Stack Overflow

Replace string in dataframe with different column values

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related