Patterns 'circle', 'pch', 'regular_polygon', 'rose' - Parameters and Examples

In ggpattern: 'ggplot2' Pattern Geoms

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  dev = "ragg_png",
  fig.width = 6, 
  fig.height = 4
)

suppressPackageStartupMessages({
  library(ggplot2)
  library(ggpattern)
})

Introduction to the 'circle', 'pch', 'regular_polygon', and 'rose' patterns

• The 'circle' pattern draws circles
• The 'pch' pattern draws "plotting character" symbols as in graphics::points()
• The 'regular_polygon' pattern draws convex/star regular polygons
• The 'rose' pattern draws rose curves

• For more info on these patterns see their {gridpattern} documentation:

• help("grid.pattern_circle", package = "gridpattern")

• help("grid.pattern_pch", package = "gridpattern")
• help("grid.pattern_regular_polygon", package = "gridpattern")
• help("grid.pattern_rose", package = "gridpattern")

Pattern Parameters

| aesthetic | description | default | possible values | |---------------------------|-----------------------------------------------|-----------|-----------------------------------| | pattern_colour | Stroke colour | 'grey20' | colour | | pattern_fill | Fill colour | 'grey80' | colour | | pattern_angle | Rotation angle | 30 | angle in degrees | | pattern_density | Approx. fraction of area the pattern fills | 0.2 | value in range [0, 1] (fraction) | | pattern_spacing | Spacing between repetitions of pattern | 0.05 | value in range [0, 1] (snpc units) | | pattern_xoffset | Shift pattern along x axis | 0 | value in range [0, 1] (snpc units) | | pattern_yoffset | Shift pattern along y axis | 0 | value in range [0, 1] (snpc units) | | pattern_alpha | Alpha | NA | value in range [0, 1] or NA | | pattern_linetype | Stroke linetype | 1 | linetype | | pattern_size | Stroke linewidth | 1 | linewidth | | pattern_type | Pattern type | NA | See circle, pch, regular_polygon, and rose pattern documentation | | pattern_subtype | Pattern subtype | NA | See circle, pch, regular_polygon, and rose pattern documentation | | pattern_grid | Grid type | 'square' | 'square', 'hex', or 'hex_circle' | | pattern_rot | Pattern symbol rotation angle | 0 | angle in degrees | | pattern_shape | Pattern shape | NA | See pch and regular_polygon | | pattern_frequency | Frequency | 0.1 | Angular frequency in 'rose' pattern |

There are also a number of parameters for extra control of legend sizing and aspect ratio adjustments. See the 'Pattern Parameters - Common' for more information.

Data

Standard data for all the example plots

df <- data.frame(trt = c("a", "b", "c"), outcome = c(2.3, 1.9, 3.2))
df

Vanilla ggplot2

ggplot(df, aes(trt, outcome)) +
  geom_col(aes(fill=trt),colour='black') +
  theme_bw() +
  labs(title = "Plain ggplot2")

Use the {ggpattern} geom

• Use ggpattern::geom_col_pattern() instead of ggplot2::geom_col().
• Set pattern = 'circle'
• Default legends in ggplot2 are usually too small to show off an example of the pattern, so it will usually be necessary to increase the key size.

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(aes(fill=trt),colour='black', pattern = 'circle') +
  theme_bw() +
  labs(title = "ggpattern") +
  theme(legend.key.size = unit(1.5, 'cm'))

The Density Aesthetic ('pch' example)

The aesthetic pattern_density roughly corresponds to the fraction of the filled area which should be covered by the pattern.

In the following plot the density of striping is increased to 50% of the fill area.

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(fill=trt, pattern_shape=trt),
    colour          = 'black', 
    pattern         = 'pch',
    pattern_density = 0.5
  ) +
  theme_bw() +
  labs(title = "Fixed density of 0.5 (50% of the fill area)") + 
  theme(legend.key.size = unit(1.5, 'cm'))

The Density Aesthetic as a Mapped Aesthetic

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(fill = trt, pattern_density = trt),
    colour          = 'black', 
    pattern         = 'circle'
  ) +
  theme_bw() +
  labs(title = "Aesthetic Mapping of 'trt' to Density") + 
  theme(legend.key.size = unit(1.5, 'cm'))

The Density Aesthetic as a Mapped Aesthetic with Manual Scale

scale_pattern_density_manual() can be used to manually control how the variable is mapped to the density.

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(fill = trt, pattern_density = trt),
    colour          = 'black', 
    pattern         = 'regular_polygon',
    pattern_shape   = 'convex6',
    pattern_fill    = 'white',
    pattern_colour  = NA,
    pattern_grid    = 'hex'
  ) +
  theme_bw() +
  labs(title = "Aesthetic Mapping of 'trt' to Density") + 
  theme(legend.key.size = unit(1.5, 'cm')) + 
  scale_pattern_density_manual(values = c(a = 0.7, b=0.8, c=0.9))

The Spacing Aesthetic as a Mapped Aesthetic

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(fill = trt, pattern_spacing = trt, pattern_shape = trt),
    pattern_density = 0.7,
    colour          = 'black', 
    pattern         = 'regular_polygon',
    pattern_scale   = 0.2
  ) +
  theme_bw() +
  labs(title = "Aesthetic Mapping of 'trt' to Spacing") + 
  scale_pattern_shape_manual(values = c(a = "circle", b = "convex3", c = "star5")) +
  theme(legend.key.size = unit(1.5, 'cm'))

The Fill Aesthetic as a Mapped Aesthetic ('rose' example)

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(fill = trt, pattern_fill = trt),
    colour          = 'black', 
    pattern         = 'rose',
    pattern_frequency = 5/2,
    pattern_density = 0.7,
    pattern_spacing = 0.15
  ) +
  theme_bw() +
  labs(title = "Aesthetic Mapping of 'trt' to Pattern Fill") + 
  scale_pattern_fill_viridis_d() + 
  theme(legend.key.size = unit(1.5, 'cm'))

ggpattern documentation built on Nov. 10, 2022, 6:03 p.m.