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Fill individual cells in a gt table by a condition

Source: R/gt_highlight_cells.R
gt_highlight_cells.Rd

Fills each cell in a block of columns that meets a condition and leaves the rest alone. It is the per-cell counterpart to gtExtras::gt_highlight_cols() and gtExtras::gt_highlight_rows(), which fill a whole column or a whole row. The condition is tested against every cell on its own, so a scattered set of cells can be filled in one call.

Usage

gt_highlight_cells(
  gt_object,
  columns,
  condition,
  fill = "#FFF3B0",
  text_color = NULL,
  bold = FALSE,
  ...
)

Arguments

gt_object

A gt table object to modify.

columns

The block of columns to test, the body of the grid.

condition

How a cell is chosen. Either a function or a right-hand-side formula applied to each column and returning a logical vector (~ .x > 0.7, ~ grepl("home", .x), ~ is.na(.x)), or a logical matrix or data frame the same shape as columns for a mask computed ahead of time.

fill

Character. The cell fill color. Defaults to "#FFF3B0", a soft yellow.

text_color

Optional. A hex color for the text in filled cells. Defaults to NULL, which leaves the text color alone.

bold

Logical. Should filled cells be bolded? Defaults to FALSE.

...

Additional arguments passed to gt::cell_text() for the filled cells, such as style = "italic".

Value

Returns a modified gt table with the matching cells filled.

Details

A single gt::tab_style() with gt::cells_body() cannot do this, since it reads rows and columns as a rectangle, every selected row crossed with every selected column. Filling a diagonal, a checker pattern, or any scatter otherwise takes a loop over the columns, one pass each. This wraps that loop.

Each selected column is filled independently, so the pattern can be a diagonal, a checker, or any scatter of cells.

The condition reads the underlying data rather than the rendered cell, so a test like ~ grepl("home", .x) sees whatever value the column holds, HTML and all. A formula or function must return one logical per row, and NA counts as not matched. For more than one color, layer the calls, one per color.

See also

gtExtras::gt_highlight_cols() and gtExtras::gt_highlight_rows() for whole-column and whole-row fills.

Examples

if (FALSE) { # \dontrun{
library(gt)

# a correlation matrix: flag strong pairs, but not the diagonal of ones
m <- round(cor(mtcars[, c("mpg", "disp", "hp", "wt", "qsec")]), 2)
cordf <- data.frame(var = rownames(m), m, row.names = NULL, check.names = FALSE)
cordf %>%
  gt(rowname_col = "var") %>%
  gt_highlight_cells(-var, ~ .x > 0.7 & .x < 1, fill = "#FFD1A9") %>%
  gt_highlight_cells(-var, ~ .x < -0.7, fill = "#A9D0FF")

# a schedule matrix: home games one color, byes another
sched <- data.frame(
  team = c("Alpha", "Bravo", "Charlie"),
  wk1 = c("vs X", "@ Y", "BYE"),
  wk2 = c("@ W", "vs V", "@ U")
)
gt(sched) %>%
  gt_highlight_cells(c(wk1, wk2), ~ grepl("^vs", .x), fill = "#CCE7F5") %>%
  gt_highlight_cells(c(wk1, wk2), ~ .x == "BYE", fill = "#D9D9D9")
} # }