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rrandomadditionsubtraction

Function that do addition or subtraction randomly

I wonder if there is a function that can do addition or subtraction operator randomly:

x +- y
Solution

  • The question boils down to getting -1 or 1 in random fashion. You can get it using sample:

    x + sample(c(-1,1),size=1)*y

    or runif:

    x + sign(runif(n=1,min=-1,max=1))*y

    If x and y are vectors, you can generate sequence of numbers -1 and 1 of the same length as the length of x, as @BondedDust suggested:

    x + sample(c(-1,1),size=length(x),replace=T)*y