set.seed(1) # constant seed for reproducibility

df = data.frame(samples = c(rnorm(200, 1, 1),

rnorm(200, 0, 1),

rnorm(200, 0, 2)))

df$parameter[1:200] = "$\\mathcal{N}(1, 1)$"

df$parameter[201:400] = "$\\mathcal{N}(0, 1)$"

df$parameter[401:600] = "$\\mathcal{N}(0, 2)$"

qplot(samples,

bins = 30,

facets = parameter~.,