There seems to be some problem with OSAT that doesn't return the same size of data that was used for input:
library("OSAT") data(survey, package = "MASS") VoI <- c("Sex", "Smoke", "Age") n_batch <- 3 iterations <- 10 gs <- setup.sample(survey, optimal = VoI) gc <- setup.container(IlluminaBeadChip96Plate, n = n_batch, batch = 'plates') gSetup <- create.optimized.setup(sample = gs, container = gc, nSim = iterations) #> Warning in create.optimized.setup(sample = gs, container = gc, nSim = #> iterations): Using default optimization method: optimal.shuffle OSAT_index <- get.experiment.setup(gSetup) dim(survey) #>  237 12 dim(OSAT_index) #>  236 19
Created on 2021-04-14 by the [reprex package](https://reprex.tidyverse.org) (v2.0.0)
Inspecting the data it seems to be the sample 137 which on the first column has an NA. But couldn't find a confirmation this is the reason.