Finding duplicate values in r

Question

So, In a string containing multiple 1\'s,

Now, it is possible that, the number

\'1\' 

appears at several positions, let\'s say, at m

Answer 1

This is not a complete answer, but some ideas (partly based on comments):

z <- "1101101101"
zz <- as.numeric(strsplit(z,"")[[1]])

Compute autocorrelation function and draw plot: in this case I'm getting the periodicity=3 pretty crudely as the first point at which there is an increase followed by a decrease ...

a1 <- acf(zz)
first.peak <- which(diff(sign(diff(a1$acf[,,1])))==-2)[1]

Now we know the periodicity is 3; create runs of 3 with embed() and analyze their similarities:

ee <- embed(zz,first.peak)
pp <- apply(ee,1,paste,collapse="")
mm <- outer(pp,pp,"==")
aa <- apply(mm[!duplicated(mm),],1,which)
sapply(aa,length)  ## 3 3 2   ## number of repeats
sapply(aa,function(x) unique(diff(x)))  ## 3 3 3