annotation of variables / features (data frame)
annotation of observations (data frame)
matrix of dimensions #observations × #variables (dense matrix or sparse matrix)
unstruct. annotation (list)
$uns
variable 1
variable 2
variable $n_var
$X
$var
$obs
variable names: $var_names
variables annotation 1
variables annotation 2
observation 1
observation 2
observation $n_obs
obs. names: $obs_names
observations annotation 1
observations annotation 2
unstruct. ann. 1
unstruct. ann. 2
now in