add_header: Add header rows with one value per column

In flextable: Functions for Tabular Reporting

Add header rows with one value per column

Description

Add new rows to the header where each value maps to a named column. Unlike add_header_row() where labels can span multiple columns, here each value fills exactly one column.

If some columns are not provided, they will be replaced by NA and displayed as empty.

Usage

add_header(x, top = TRUE, ..., values = NULL)

Arguments

x	a 'flextable' object, see flextable-package to learn how to create 'flextable' object.
top	should the rows be inserted at the top or the bottom.
...	named arguments (names are data colnames) of values to add. It is important to insert data of the same type as the original data, otherwise it will be transformed (probably into strings if you add a character where a double is expected). This makes possible to still format cell contents with the ⁠colformat_*⁠ functions, for example colformat_num().
values	a list of name-value pairs of labels or values, names should be existing col_key values. This argument can be used instead of ... for programming purpose (If values is supplied argument ... is ignored).

Note

when repeating values, they can be merged together with function merge_h() and merge_v().

See Also

Other row and column operations: add_body(), add_body_row(), add_footer(), add_footer_lines(), add_footer_row(), add_header_lines(), add_header_row(), delete_columns(), delete_part(), delete_rows(), paginate(), separate_header(), set_header_footer_df, set_header_labels(), split_columns(), split_rows(), split_to_pages()

Examples

library(flextable)

fun <- function(x) {
  paste0(
    c("min: ", "max: "),
    formatC(range(x))
  )
}
new_row <- list(
  Sepal.Length = fun(iris$Sepal.Length),
  Sepal.Width =  fun(iris$Sepal.Width),
  Petal.Width =  fun(iris$Petal.Width),
  Petal.Length = fun(iris$Petal.Length)
)

ft_1 <- flextable(data = head(iris))
ft_1 <- add_header(ft_1, values = new_row, top = FALSE)
ft_1 <- append_chunks(ft_1, part = "header", i = 2, )
ft_1 <- theme_booktabs(ft_1, bold_header = TRUE)
ft_1 <- align(ft_1, align = "center", part = "all")
ft_1

flextable documentation built on June 2, 2026, 9:08 a.m.