---
title: "Patterns 'circle', 'pch', 'regular_polygon', 'rose' - Parameters and Examples"
output:
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toc: true
vignette: >
%\VignetteIndexEntry{Patterns 'circle', 'pch', 'regular_polygon', 'rose' - Parameters and Examples}
%\VignetteEngine{knitr::rmarkdown}
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---
```{r, include = FALSE}
knitr::opts_chunk$set(
collapse = TRUE,
comment = "#>",
dev = "ragg_png",
fig.width = 6,
fig.height = 4
)
```
```{r setup}
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](https://en.wikipedia.org/wiki/Rose\_(mathematics))
* For more info on these patterns see their `{gridpattern}` documentation:
* [`help("grid.pattern_circle", package = "gridpattern")`](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern_circle.html)
* [`help("grid.pattern_pch", package = "gridpattern")`](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern_pch.html)
* [`help("grid.pattern_regular_polygon", package = "gridpattern")`](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern_regular_polygon.html)
* [`help("grid.pattern_rose", package = "gridpattern")`](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern_rose.html)
## 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 `pattern_units` grid units |
| pattern\_xoffset | Shift pattern along x axis | 0 | value in `pattern_units` grid units |
| pattern\_yoffset | Shift pattern along y axis | 0 | value in `pattern_units` grid units |
| pattern\_units | Pattern grid unit | 'snpc' | `grid::unit()` unit i.e. 'snpc', 'cm', and 'inches' |
| 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](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_circle.html), [pch](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_pch.html), [regular\_polygon](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_regular\_polygon.html), and [rose](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_rose.html) pattern documentation |
| pattern\_subtype | Pattern subtype | NA | See [circle](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_circle.html), [pch](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_pch.html), [regular\_polygon](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_regular\_polygon.html), and [rose](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_rose.html) 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](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_pch.html) and [regular\_polygon](https://trevorldavis.com/R/gridpattern/dev/reference/grid.pattern\_regular\_polygon.html) |
| 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
```{r}
df <- data.frame(trt = c("a", "b", "c"), outcome = c(2.3, 1.9, 3.2))
df
```
## Vanilla ggplot2
```{r plain, fig.cap="", fig.alt="Example of a plain 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.
```{r ggpattern, fig.cap="", fig.alt="Example using ggpattern to make patterned geoms"}
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.
```{r density, fig.cap="", fig.alt="Example of increasing density of striping"}
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
```{r density2, fig.cap="", fig.alt="Example from using 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.
```{r density3, fig.cap="", fig.alt="Example from using the density aesthetic as a mapped aesthetic with manual scale."}
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
```{r spacing, fig.cap="", fig.alt="Example from using 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)
```{r fill, fig.cap="", fig.alt="Example from using the fill aesthetic as a mapped aesthetic."}
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'))
```