format_tt function

Format columns of a data frame

This function formats the columns of a data frame based on the column type (logical, date, numeric). It allows various formatting options like significant digits, decimal points, and scientific notation. It also includes custom formatting for date and boolean values. If this function is applied several times to the same cell, the last transformation is retained and the previous calls are ignored, except for the escape argument which can be applied to previously transformed data.

format_tt(
  x,
  i = NULL,
  j = NULL,
  digits = get_option("tinytable_format_digits", default = NULL),
  num_fmt = get_option("tinytable_format_num_fmt", default = "significant"),
  num_zero = get_option("tinytable_format_num_zero", default = FALSE),
  num_suffix = get_option("tinytable_format_num_suffix", default = FALSE),
  num_mark_big = get_option("tinytable_format_num_mark_big", default = ""),
  num_mark_dec = get_option("tinytable_format_num_mark_dec", default =
    getOption("OutDec", default = ".")),
  date = get_option("tinytable_format_date", default = NULL),
  bool = get_option("tinytable_format_bool", default = NULL),
  math = get_option("tinytable_format_math", default = FALSE),
  other = get_option("tinytable_format_other", default = NULL),
  replace = get_option("tinytable_format_replace", default = FALSE),
  escape = get_option("tinytable_format_escape", default = FALSE),
  markdown = get_option("tinytable_format_markdown", default = FALSE),
  quarto = get_option("tinytable_format_quarto", default = FALSE),
  fn = get_option("tinytable_format_fn", default = NULL),
  sprintf = get_option("tinytable_format_sprintf", default = NULL)
)

Arguments

• x: A data frame or a vector to be formatted.

• i: Row indices where the formatting should be applied.

• j: Column indices where the styling should be applied. Can be:

  • Integer vectors indicating column positions.
  • Character vector indicating column names.
  • A single string specifying a Perl-style regular expression used to match column names.

• digits: Number of significant digits or decimal places.

• num_fmt: The format for numeric values; one of 'significant', 'significant_cell', 'decimal', or 'scientific'.

• num_zero: Logical; if TRUE, trailing zeros are kept in "decimal" format (but not in "significant" format).

• num_suffix: Logical; if TRUE display short numbers with digits significant digits and K (thousands), M (millions), B (billions), or T (trillions) suffixes.

• num_mark_big: Character to use as a thousands separator.

• num_mark_dec: Decimal mark character. Default is the global option 'OutDec'.

• date: A string passed to the format() function, such as "%Y-%m-%d". See the "Details" section in ?strptime

• bool: A function to format logical columns. Defaults to title case.

• math: Logical. If TRUE, wrap cell values in math mode $..$. This is useful for LaTeX output or with HTML MathJax options(tinytable_html_mathjax=TRUE).

• other: A function to format columns of other types. Defaults to as.character().

• replace: Logical, String or Named list of vectors

  • TRUE: Replace NA and NaN by an empty string.

  • FALSE: Print NA and NaN as strings.

  • String: Replace NA and NaN entries by the user-supplied string.

  • Named list: Replace matching elements of the vectors in the list by theirs names. Example:

    • list("-" = c(NA, NaN), "Tiny" = -Inf, "Massive" = Inf)

• escape: Logical or "latex" or "html". If TRUE, escape special characters to display them as text in the format of the output of a tt() table.

  • If i and j are both NULL, escape all cells, column names, caption, notes, and spanning labels created by group_tt().

• markdown: Logical; if TRUE, render markdown syntax in cells. Ex: _italicized text_ is properly italicized in HTML and LaTeX.

• quarto: Logical. Enable Quarto data processing and wrap cell content in a data-qmd span (HTML) or \QuartoMarkdownBase64{} macro (LaTeX). See warnings in the Global Options section below.

• fn: Function for custom formatting. Accepts a vector and returns a character vector of the same length.

• sprintf: String passed to the ?sprintf function to format numbers or interpolate strings with a user-defined pattern (similar to the glue package, but using Base R).

Returns

A data frame with formatted columns.

Global options

Options can be set with options() and change the default behavior of tinytable. For example:

options(tinytable_tt_digits = 4)
tt(head(iris))

You can set options in a script or via .Rprofile. Note: be cautious with .Rprofile settings as they may affect reproducibility.

Default values for function arguments

tt()

• tinytable_tt_digits
• tinytable_tt_caption
• tinytable_tt_notes
• tinytable_tt_width
• tinytable_tt_theme
• tinytable_tt_rownames

format_tt()

• tinytable_format_digits
• tinytable_format_num_fmt
• tinytable_format_num_zero
• tinytable_format_num_suffix
• tinytable_format_num_mark_big
• tinytable_format_num_mark_dec
• tinytable_format_date
• tinytable_format_bool
• tinytable_format_other
• tinytable_format_replace
• tinytable_format_escape
• tinytable_format_markdown
• tinytable_format_quarto
• tinytable_format_fn
• tinytable_format_sprintf

save_tt()

• tinytable_save_overwrite

theme_tt()

Placement:

• tinytable_theme_placement_float
• tinytable_theme_placement_horizontal

Resize:

• tinytable_theme_resize_width
• tinytable_theme_resize_direction

Multipage:

• tinytable_theme_multipage_rowhead
• tinytable_theme_multipage_rowfoot

Tabular:

• tinytable_theme_tabular_style

print.tinytable()

• tinytable_print_output

Output-specific options

HTML

• tinytable_html_mathjax: Insert MathJax scripts (warning: may conflict if MathJax is loaded elsewhere)
• tinytable_html_portable: Insert base64 encoded images directly in HTML for plot_tt()

PDF

• tinytable_pdf_clean: Delete temporary and log files
• tinytable_pdf_engine: Choose between "xelatex", "pdflatex", "lualatex"

Quarto

The format_tt(quarto=TRUE) argument enables Quarto data processing with some limitations:

1. The \QuartoMarkdownBase64{} LaTeX macro may not process references and markdown as expected
2. Quarto processing may conflict with tinytable styling/formatting

Options:

• tinytable_quarto_disable_processing: Disable Quarto cell processing
• tinytable_print_rstudio_notebook: Display tables "inline" or in "viewer" for RStudio notebooks
• tinytable_quarto_figure: Control Typst figure environment in Quarto

Example of Quarto-specific code in cells:

x <- data.frame(Math = "x^2^", Citation = "@Lovelace1842")
fn <- function(z) sprintf("<span data-qmd='%s'></span>", z)
tt(x) |> format_tt(i = 1, fn = fn)

For more details on Quarto table processing: https://quarto.org/docs/authoring/tables.html#disabling-quarto-table-processing

Examples

dat <- data.frame(
  a = rnorm(3, mean = 10000),
  b = rnorm(3, 10000)
)
tab <- tt(dat)
format_tt(tab,
  digits = 2,
  num_mark_dec = ",",
  num_mark_big = " "
)

k <- tt(data.frame(x = c(0.000123456789, 12.4356789)))
format_tt(k, digits = 2, num_fmt = "significant_cell")

dat <- data.frame(
  a = c("Burger", "Halloumi", "Tofu", "Beans"),
  b = c(1.43202, 201.399, 0.146188, 0.0031),
  c = c(98938272783457, 7288839482, 29111727, 93945)
)
tt(dat) |>
  format_tt(j = "a", sprintf = "Food: %s") |>
  format_tt(j = 2, digits = 1, num_fmt = "decimal", num_zero = TRUE) |>
  format_tt(j = "c", digits = 2, num_suffix = TRUE)

y <- tt(data.frame(x = c(123456789.678, 12435.6789)))
format_tt(y, digits = 3, num_mark_big = " ")

x <- tt(data.frame(Text = c("_italicized text_", "__bold text__")))
format_tt(x, markdown = TRUE)

tab <- data.frame(a = c(NA, 1, 2), b = c(3, NA, 5))
tt(tab) |> format_tt(replace = "-")

dat <- data.frame(
  "LaTeX" = c("Dollars $", "Percent %", "Underscore _"),
  "HTML" = c("<br>", "<sup>4</sup>", "<emph>blah</emph>")
)
tt(dat) |> format_tt(escape = TRUE)