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Specify fill patterns

Source: R/tm_patterns.R
tm_patterns.Rd

Specify fill patterns for the map variable pattern (see tm_polygons()), either as constant value or as values of a scale, e.g. tm_scale_categorical(). The arguments are vectorized, so one call can specify several patterns. A plain character vector of pattern types and shortcuts can also be used instead, as well as a list of tm_patterns() calls.

Usage

tm_patterns(
  type = "hatch",
  angle = NA,
  random = NA,
  length = NA,
  amplitude = NA
)

Arguments

type

Pattern type or shortcut. See details.

angle

Angle of the motif in degrees, counter-clockwise from horizontal. For "hatch", 0 means horizontal lines and 45 lines from lower left to upper right.

random

Randomness of the placement of dots, circles, or crosses, between 0 (regular grid) and 1 (maximal random displacement within the grid cell). Elements do not clump, since each grid cell contains one element.

length

Length of dashes, bricks, or herringbone blocks, relative to the spacing.

amplitude

Amplitude of waves and zigzag lines, relative to the spacing.

Value

A character vector of class tmap_patterns with one pattern specification per element.

Details

Pattern types:

TypeParameters
"none"–
"hatch"angle (default 45)
"crosshatch"angle (default 0)
"dots"random (default 0)
"dashes"angle (default 0), length (default 0.5)
"bricks"angle (default 0), length (default 2)
"herringbone"angle (default 0), length (default 2)
"hexagons"angle (default 0)
"waves"angle (default 0), amplitude (default 0.25)
"zigzag"angle (default 0), amplitude (default 0.25)
"circles"random (default 0)
"crosses"random (default 0)
"noise"–

Shortcuts: "hatch_up" (same as "hatch"), "hatch_down" (angle 135), "hatch_horizontal" (angle 0), "hatch_vertical" (angle 90), "crosshatch_diagonal" (crosshatch with angle 45), and "stipple" (dots with random = 0.7).

The spacing between the pattern elements is determined by the map variable pattern_density, the line width or dot size by pattern_size, and the color by pattern_col. The parameters length and amplitude are relative to that spacing, so the whole motif is scaled with the density.

See also

tm_polygons()

Examples

tm_patterns("hatch", angle = c(0, 45, 90, 135))
#> [1] "hatch(angle=0)"   "hatch(angle=45)"  "hatch(angle=90)"  "hatch(angle=135)"
tm_patterns(c("dots", "stipple", "bricks"))
#> [1] "dots(random=0)"           "dots(random=0.7)"        
#> [3] "bricks(angle=0,length=2)"

# as values of a scale
tm_shape(World) +
  tm_polygons(pattern = "economy",
    pattern.scale = tm_scale_categorical(values = tm_patterns(c("hatch", "dots", "bricks"))))
#> Warning: [pattern] the number of patterns (3) is smaller than the number of classes (7),
#> so patterns are recycled