# NOT RUN {
## Generate data
n <- 1000 # sample size
d <- 100 # dimension
set.seed(271) # set seed
x <- matrix(runif(n*d), ncol = d) # generate data
## Assign missing data
k <- ceiling(d/4) # fraction of columns with some NAs
j <- sample(1:d, size = k) # columns j with NAs
i <- sample(1:n, size = k) # 1:i will be NA in each column j
X <- x
for(k. in seq_len(k)) X[1:i[k.], j[k.]] <- NA # put in NAs
## Plot NAs
NA_plot(X) # indicate NAs
# }
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