Show the available values of categorical map variables

Draws the values of a categorical map variable (other than color), each labeled with the code that specifies it. These codes can be used as constant values (e.g. tm_symbols(shape = 22)) and as values of a scale (e.g. tm_scale_categorical(values = c("hatch", "dots"))). For color palettes, see cols4all::c4a_gui().

Usage

tmap_show_values(
  variable = c("pattern", "shape", "lty", "fontface"),
  values = NULL,
  col = "grey20",
  fill = "grey90",
  ncol = NA
)

Arguments

variable

the map variable: one of "pattern" (see tm_polygons()), "shape" (see tm_symbols()), "lty" (line type, see e.g. tm_lines()), and "fontface" (see tm_text()).

values

the values to show. By default (NULL), all available values. See details.

col

the color of the lines, the borders of symbols, the patterns, and the text.

fill

the fill color of polygons ("pattern") and of the symbols with a fill (shapes 21 to 25).

ncol

number of columns. By default, determined by the number of values.

Value

The values shown (invisibly), as codes that can be used as values of a scale. When several pattern sets are shown, a list with one element per set.

Details

By default, all available values are shown. With values, specific values are shown instead, in the same form as the values argument of a scale, such as tm_scale_categorical():

variable	Available values	Other values
"pattern"	pattern types and shortcuts (see tm_patterns())	pattern sets: "mixed" (the default of scales), "classic", "lines", and "shapes"; tm_patterns() specifications
"shape"	0 to 25 (see graphics::points())
"lty"	"solid", "dashed", "dotted", "dotdash", "longdash", and "twodash"	strings of 2, 4, 6, or 8 hexadecimal digits, the lengths of the dashes and gaps (e.g. "44"; see graphics::par())
"fontface"	"plain", "italic", "bold", and "bold.italic"

A pattern set is shown as a group of patterns, in the order in which they are used: a scale with n categories takes the first n patterns of the set. Several sets can be shown at once, e.g. all sets with values = c("mixed", "classic", "lines", "shapes").

See also

tm_patterns(), tm_symbols(), tm_lines(), tm_text()

Examples

# all pattern types and shortcuts
tmap_show_values("pattern")


# a pattern set, in the order of use, and all pattern sets
tmap_show_values("pattern", values = "classic")

tmap_show_values("pattern", values = c("mixed", "classic", "lines", "shapes"))


# specific patterns
tmap_show_values("pattern", values = tm_patterns("hatch", angle = c(0, 30, 60)))


tmap_show_values("shape")

tmap_show_values("lty")

tmap_show_values("lty", values = c("44", "13", "1343"))

tmap_show_values("fontface")