Patterns 'stripe', 'wave', 'crosshatch', 'weave' - Parameters and Examples

In ggpattern: 'ggplot2' Pattern Geoms

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  dev = "ragg_png",
  fig.width = 7, 
  fig.height = 4
)

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

Introduction to the 'stripe', 'wave', 'crosshatch', and 'weave' patterns

• The 'stripe' pattern draws a set of (horizontal) straight lines.
• The 'wave' pattern draws a set of (horizontal) wavy lines.
• The 'crosshatch' pattern draws a set of vertical lines on top of a set of horizontal lines.
• The 'weave' pattern draws a set of vertical lines interlaced with a set of horizontal lines.

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

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

• help("grid.pattern_wave", package = "gridpattern")
• help("grid.pattern_crosshatch", package = "gridpattern")
• help("grid.pattern_weave", 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 wave and weave pattern documentation | | pattern_subtype | Pattern subtype | NA | See weave pattern documentation | | pattern_frequency | Frequency | 0.1 | Frequency of waves in 'wave' 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 = 'stripe'
• 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='stripe') +
  theme_bw() +
  labs(title = "ggpattern") +
  theme(legend.key.size = unit(1.5, 'cm'))

Mixing patterns

• Often we'll want to mix patterns.
  To get the legend right we'll often want to set them with a pattern scale function like 'pattern_scale_manual()' instead of simply setting them with the 'pattern' aesthetic.
• Here we'll use the 'stripe' pattern and 'wave' pattern.
• The 'wave' pattern supports two subtypes: 'triangle' waves (default) have a zig-zag appearance whereas 'sine' waves have a curvy appearance.

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(aes(fill=trt, pattern=trt, pattern_type=trt),colour='black') + 
  theme_bw() +
  labs(title = "Use 'stripe' and 'wave' patterns") + 
  theme(legend.key.size = unit(1.5, 'cm')) +
  scale_pattern_manual(values=c('stripe', 'wave', 'wave')) +
  scale_pattern_type_manual(values=c(NA, 'triangle', 'sine'))

The Density Aesthetic

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=trt),
    colour          = 'black', 
    pattern_density = 0.5
  ) +
  theme_bw() +
  labs(title = "Fixed density of 0.5 (50% of the fill area)") + 
  scale_pattern_manual(values=c('stripe', 'crosshatch', 'weave')) +
  theme(legend.key.size = unit(1.5, 'cm'))

Weave types

The 'weave' pattern supports a rich set of weave types and subtypes including irregular 'matt', 'twill' (including 'herringbone' and 'zigzag' variations), and 'satin' weaves . See the weave pattern documentation for more information.

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(pattern_fill2=trt, pattern_type=trt),
    pattern = 'weave',
    colour          = 'black', 
    pattern_density = 1.0,
    pattern_fill = 'grey',
    pattern_key_scale_factor = 0.5,
  ) +
  theme_bw() +
  labs(title = "Some 'weave' types") + 
  scale_pattern_type_manual(values=c('plain', 'twill', 'satin')) +
  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         = 'stripe'
  ) +
  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         = 'stripe'
  ) +
  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 = 0.1, b=0.3, c=0.5))

The Spacing Aesthetic as a Mapped Aesthetic

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

The Fill Aesthetic as a Mapped Aesthetic

ggplot(df, aes(trt, outcome)) +
  geom_col_pattern(
    aes(fill = trt, pattern_fill = trt),
    colour          = 'black', 
    pattern         = 'stripe'
  ) +
  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.