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Plot an individual FGDC pattern using grid

Source: R/patterns.R
grid.pattern_geo.Rd

This function can be used to plot a single geologic pattern as defined in the FGDC Digital Cartographic Standard for Geologic Map Symbolization by the U.S. Geological Survey and the Geologic Data Subcommittee (GDS) of the Federal Geographic Data Committee (FGDC). The pattern is plotted on the existing canvas (i.e., use grid::grid.newpage() to make a new canvas).

Usage

grid.pattern_geo(params, boundary_df, aspect_ratio, legend = FALSE)

Arguments

params

A list of pattern parameters to customize the plotted pattern (see "Details").

boundary_df

A data.frame consisting of three columns: "x" (x-coordinates), "y" (y-coordinates), and "id" (polygon group ID). This data.frame defines the boundary (as a closed polygon) of the plotted pattern.

aspect_ratio

Unused.

legend

Unused.

Details

The following params are accepted:

pattern_alpha

Alpha transparency for pattern. default: 1

pattern_colour

Color used for strokes and points in the pattern. default: 'black'

pattern_fill

Color used to fill various closed shapes (e.g., circles) in the pattern. default: NA

pattern_scale

Scale. default: 2

pattern_type

Code for the FGDC pattern to use. See geo_pattern() for more details. default: "101"

fill

Color used for the background. default: "white"

Warning

Pattern fills are not supported on all graphics devices. Not all devices are under active development, and such devices are unlikely to add support for new features (such as pattern fills). The new features have only been implemented on a subset of graphics devices so far: cairo_pdf(), cairo_ps(), x11(type="cairo"), png(type="cairo"), jpeg(type="cairo"), tiff(type="cairo"), svg(), and pdf(). Although there is no support yet for quartz() or windows(), almost all of the graphics devices above will work on all major platforms. Further, the ragg and svglite packages contain graphics devices that support patterns. When using a graphics device where patterns are not supported, closed shapes will be rendered with a transparent fill. Note that, at least on Windows machines, the default device in RStudio and in the knitr package is png(), which does not support patterns. In RStudio, you can go to ‘Tools > Global Options > General > Graphics’ and choose the ‘Cairo PNG’ device from the dropdown menu to display patterns. Similar issues may arise when using RStudio on other operating systems.

See also

FGDC patterns: geo_pattern(), scale_fill_geopattern()

Examples

# use the function directly to make a hexagon with the pattern
library(grid)
x <- 0.5 + 0.5 * cos(seq(2 * pi / 4, by = 2 * pi / 6, length.out = 6))
y <- 0.5 + 0.5 * sin(seq(2 * pi / 4, by = 2 * pi / 6, length.out = 6))
grid.newpage()
grid.pattern_geo(params = list(pattern_type = "633", pattern_scale = 4),
                 boundary_df = data.frame(x, y, id = 1))

# use the function via ggpattern by specifying `pattern = 'geo'`
library(ggplot2)
library(ggpattern)
df <- data.frame(trt = c("a", "b", "c"), outcome = c(2.3, 1.9, 3.2))
ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(aes(color = trt, pattern_type = trt), pattern = 'geo',
  pattern_color = "black", fill = "white", pattern_fill = "white") +
  scale_pattern_type_manual(values = c("101", "313", "634")) +
  scale_color_viridis_d() +
  theme(legend.key.size = unit(1.5, 'cm'))