Linear discriminant analysis preparation

Removes NAs, constant and collinear columns. Useful to speed up calculations when used with stat_lda0

stat_lda_prepare(
  x,
  f,
  ...,
  constant_below_var = 1e-05,
  collinear_above_cor = 1 - 1e-05
)

Arguments

x	tibble, typically a coe_tbl
f	column specifying grouping factor
...	columns specifying those to use
constant_below_var	numeric threshold under which columns will be considered constant (using stats::var) and dropped (default to 1e-5)
collinear_above_cor	numeric threshold above which columns will be considered collinear (using stats::cor), and dropped (default to 1-1e-5)