CODEWITHSUNDEEP
rlist
lightsnail
lightsnail

Reputation: 788

replace values of a list with another in R

a,b and c are list.

a<-list(c(6,5,7),c(1,2),c(1,3,4))
b<-list(c(1,2,3),c(4,5),c(6,7,8))
c<-list(1,2,2)

I want to replace "a" with "b" at place "c" to generate a new list.

The expected result is as follows:

[[1]]
[1] 1 5 7

[[2]]
[1] 1 5

[[3]]
[1] 1 7 4

Thank you for help!

Upvotes: 4

Views: 2733

Answers (2)

Marc in the box
Marc in the box

Reputation: 12005

For the R newbies that find that find the syntax of Map daunting:

for(i in seq(c)){
  a[[i]][unlist(c[i])] <- b[[i]][unlist(c[i])]
}
a

# [[1]]
# [1] 1 5 7
#
# [[2]]
# [1] 1 5
#
# [[3]]
# [1] 1 7 4

Upvotes: 0

MrFlick
MrFlick

Reputation: 206566

Sounds like you're looking for Map to iterate over all the lists simultaneously.

Map(function(a,b,c) {a[c]<-b[c]; a},a,b,c)
# [[1]]
# [1] 1 5 7
#
# [[2]]
# [1] 1 5
#
# [[3]]
# [1] 1 7 4

Upvotes: 8

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