If you use NULL
as an argument for set.seed
, the RNG will produce different results.
> set.seed(NULL)
> rnorm(5)
[1] -0.45861478 -0.56525262 -0.95349202 0.05073898 -1.01956671
> set.seed(NULL)
> rnorm(5)
[1] 0.57787302 3.27165390 0.53466909 -1.15390604 -0.02624054
I recommend using the sequence
set.seed(NULL)
mice(...) # without seed argument