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Should replicate analyses of ADMIXTURE all have the same cross-validation values

This is a pretty simple question. I have noticed when I run my ADMIXTURE values for K=2 to 20 with ten replicates, my output CV values for each value of K are always identical for all 10 replicates. I've seen literature where there is some variation in replicate CVs. They do have different loglikelihoods, but the CVs fall out the same.

I was wondering, is this normal?

admixture
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updated by Ram Ram • written by devenvyas devenvyas

2 answers

I have also noticed identical CV-error values for every replicate ADMIXTURE run. This is due to the initial seed number that is always 43. There is an option of generating a pseudo-random seed using the system clock (flag -s). Here is how I ran it:

admixture -s time --cv file.ped K -jN
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written by biomonte biomonte

I've seen this with my ADMIXTURE runs in the past. For what it's worth, I've noticed more variation in the likelihoods of STRUCTURE runs, meaning that there can be a bit of a difference among sets of replicates when selecting an 'optimal' K (whatever that means). That's not using cross validation, though.

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written by Brice Sarver Brice Sarver

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