Groups and labels

library(tinytable)
options(tinytable_tt_digits = 3)
options(tinytable_theme_placement_latex_float = "H")
x <- mtcars[1:4, 1:5]

The group_tt() function can label groups of rows (i) or columns (j).

Rows

The i argument accepts a named list of integers. The numbers identify the positions where row group labels are to be inserted. The names includes the text that should be inserted:

dat <- mtcars[1:9, 1:8]

tt(dat) |>
  group_tt(i = list(
    "I like (fake) hamburgers" = 3,
    "She prefers halloumi" = 4,
    "They love tofu" = 7))

mpg	cyl	disp	hp	drat	wt	qsec	vs
21	6	160	110	3.9	2.62	16.5	0
21	6	160	110	3.9	2.88	17	0
22.8	4	108	93	3.85	2.32	18.6	1
21.4	6	258	110	3.08	3.21	19.4	1
18.7	8	360	175	3.15	3.44	17	0
18.1	6	225	105	2.76	3.46	20.2	1
14.3	8	360	245	3.21	3.57	15.8	0
24.4	4	147	62	3.69	3.19	20	1
22.8	4	141	95	3.92	3.15	22.9	1

The numbers in the i list indicate that a label must be inserted at position # in the original table (without row groups). For example,

tt(head(iris)) |>
  group_tt(i = list("After 1" = 2, "After 2" = 3, "After 3" = 4, "After 5" = 6))

Sepal.Length	Sepal.Width	Petal.Length	Petal.Width	Species
5.1	3.5	1.4	0.2	setosa
4.9	3	1.4	0.2	setosa
4.7	3.2	1.3	0.2	setosa
4.6	3.1	1.5	0.2	setosa
5	3.6	1.4	0.2	setosa
5.4	3.9	1.7	0.4	setosa

tt(head(iris)) |>
  group_tt(i = list("After 1a" = 2, "After 1b" = 2, "After 5" = 6))

Sepal.Length	Sepal.Width	Petal.Length	Petal.Width	Species
5.1	3.5	1.4	0.2	setosa
4.9	3	1.4	0.2	setosa
4.7	3.2	1.3	0.2	setosa
4.6	3.1	1.5	0.2	setosa
5	3.6	1.4	0.2	setosa
5.4	3.9	1.7	0.4	setosa

tt(head(iris)) |>
  group_tt(i = list("After 0" = 1))

Sepal.Length	Sepal.Width	Petal.Length	Petal.Width	Species
5.1	3.5	1.4	0.2	setosa
4.9	3	1.4	0.2	setosa
4.7	3.2	1.3	0.2	setosa
4.6	3.1	1.5	0.2	setosa
5	3.6	1.4	0.2	setosa
5.4	3.9	1.7	0.4	setosa

We can style group rows in the same way as regular rows:

tt(dat) |>
  group_tt(
    i = list(
      "I like (fake) hamburgers" = 3,
      "She prefers halloumi" = 4,
      "They love tofu" = 7
    )
  ) |>
  style_tt(
    i = c(3, 5, 9),
    align = "c",
    color = "white",
    background = "gray",
    bold = TRUE
  )

mpg	cyl	disp	hp	drat	wt	qsec	vs
21	6	160	110	3.9	2.62	16.5	0
21	6	160	110	3.9	2.88	17	0
22.8	4	108	93	3.85	2.32	18.6	1
21.4	6	258	110	3.08	3.21	19.4	1
18.7	8	360	175	3.15	3.44	17	0
18.1	6	225	105	2.76	3.46	20.2	1
14.3	8	360	245	3.21	3.57	15.8	0
24.4	4	147	62	3.69	3.19	20	1
22.8	4	141	95	3.92	3.15	22.9	1

Automatic row groups

We can use the group_tt() function to group rows and label them using spanners (almost) automatically. For example,

# subset and sort data
df <- mtcars |>
  head(10) |>
  sort_by(~am)

# draw table
tt(df) |> group_tt(i = df$am)

mpg	cyl	disp	hp	drat	wt	qsec	vs	am	gear	carb
21.4	6	258	110	3.08	3.21	19.4	1	0	3	1
18.7	8	360	175	3.15	3.44	17	0	0	3	2
18.1	6	225	105	2.76	3.46	20.2	1	0	3	1
14.3	8	360	245	3.21	3.57	15.8	0	0	3	4
24.4	4	147	62	3.69	3.19	20	1	0	4	2
22.8	4	141	95	3.92	3.15	22.9	1	0	4	2
19.2	6	168	123	3.92	3.44	18.3	1	0	4	4
21	6	160	110	3.9	2.62	16.5	0	1	4	4
21	6	160	110	3.9	2.88	17	0	1	4	4
22.8	4	108	93	3.85	2.32	18.6	1	1	4	1

Columns

The syntax for column groups is very similar, but we use the j argument instead. The named list specifies the labels to appear in column-spanning labels, and the values must be a vector of consecutive and non-overlapping integers that indicate which columns are associated to which labels:

tt(dat) |>
  group_tt(
    j = list(
      "Hamburgers" = 1:3,
      "Halloumi" = 4:5,
      "Tofu" = 7))

Hamburgers			Halloumi			Tofu
mpg	cyl	disp	hp	drat	wt	qsec	vs
21	6	160	110	3.9	2.62	16.5	0
21	6	160	110	3.9	2.88	17	0
22.8	4	108	93	3.85	2.32	18.6	1
21.4	6	258	110	3.08	3.21	19.4	1
18.7	8	360	175	3.15	3.44	17	0
18.1	6	225	105	2.76	3.46	20.2	1
14.3	8	360	245	3.21	3.57	15.8	0
24.4	4	147	62	3.69	3.19	20	1
22.8	4	141	95	3.92	3.15	22.9	1

Here is a table with both row and column headers, as well as some styling:

dat <- mtcars[1:9, 1:8]
tt(dat) |>
  group_tt(
    i = list(
      "I like (fake) hamburgers" = 3,
      "She prefers halloumi" = 4,
      "They love tofu" = 7
    ),
    j = list(
      "Hamburgers" = 1:3,
      "Halloumi" = 4:5,
      "Tofu" = 7
    )
  ) |>
  style_tt(
    i = c(3, 5, 9),
    align = "c",
    background = "teal",
    color = "white"
  ) |>
  style_tt(i = -1, color = "teal")

Hamburgers			Halloumi			Tofu
mpg	cyl	disp	hp	drat	wt	qsec	vs
21	6	160	110	3.9	2.62	16.5	0
21	6	160	110	3.9	2.88	17	0
22.8	4	108	93	3.85	2.32	18.6	1
21.4	6	258	110	3.08	3.21	19.4	1
18.7	8	360	175	3.15	3.44	17	0
18.1	6	225	105	2.76	3.46	20.2	1
14.3	8	360	245	3.21	3.57	15.8	0
24.4	4	147	62	3.69	3.19	20	1
22.8	4	141	95	3.92	3.15	22.9	1

We can also stack several extra headers on top of one another:

tt(x) |>
  group_tt(j = list("Foo" = 2:3, "Bar" = 5)) |>
  group_tt(j = list("Hello" = 1:2, "World" = 4:5))

Hello			World
	Foo			Bar
mpg	cyl	disp	hp	drat
21	6	160	110	3.9
21	6	160	110	3.9
22.8	4	108	93	3.85
21.4	6	258	110	3.08