Make a kable with a hierarchical header

Create a knitr::kable with a multi-layered (graded) header.

grable(
    data,
    at,
    sep = "_",
    reverse = FALSE,
    format = c("html", "latex"),
    caption = NULL,
    ...
)

Arguments

data: A data.frame.
at: A vector of quoted/unquoted columns, positions, and/or tidyselect::select_helpers. Defaults to all columns.
sep: String to separate the columns. Defaults to "_".
reverse: Should the layers be added in the opposite direction? Defaults to FALSE.
format: Format for rendering the table. Must be "html" (default) or "latex".
caption: Optional caption for the table
...: Arguments to pass to kableExtra::kable_styling

Alex Zajichek