CODEWITHSUNDEEP
rvector
albert
albert

Reputation: 325

How can I randomly remove one element from a vector which satisfies given condition?

How can I remove only AN element from a vector in R? For example, 

x = c(1, 2, 0, 3, 1, 4, 2, 0)

I want to delete only one of the zeros, randomly. Then 

x = c(1, 2, 0, 3, 1, 4, 2)

or 

x = c(1, 2, 3, 1, 4, 2, 0)

Upvotes: 3

Views: 437

Answers (1)

Rich Scriven
Rich Scriven

Reputation: 99331

To randomly choose which zero gets removed, you can use 

x[-sample(which(x == 0), 1)]

Obviously the above will only work if there is at least one zero in x. As a safeguard, you can use an if() statement. 

if(length(w <- which(x == 0))) x[-sample(w, 1)] else x
# [1] 1 2 0 3 1 4 2
if(length(w <- which(x == 0))) x[-sample(w, 1)] else x
# [1] 1 2 3 1 4 2 0

Searching for 11, where there are none, we get the entire vector x back.

if(length(w <- which(x == 11))) x[-sample(w, 1)] else x
# [1] 1 2 0 3 1 4 2 0

Upvotes: 3

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