[R] Increment certain values in a vector

[Thomas Chesney]

How can I manipulate values of only certain entries in a vector, based on what the existing values are?

So for instance if I want to add one to each of the following values, or multiply them by a specific factor:

agents[which(agent$membership == 1)]

how would I do this please?

If there was just one value to manipulate I'd just do this:

value <- value + 1

and this would let me set the values:

agents[which(agent$membership == 1)] <- 100

but how to essentially achieve this:

agents[which(agent$membership == 1)] <- agents[which(agent$membership == 1)] + 1

Thank you!



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