ggrastr

https://rdrr.io/cran/ggrastr/
Admin
ggrastr is an R package that rasterizes specific layers of ggplot2 plots while preserving labels and...
Tokens:2,664
Snippets:38
Trust Score:9.9
Update:5 months ago
Show doc for...
Tokens:
Raw
### Install ggrastr Package

Source: https://rdrr.io/cran/ggrastr

Install the latest version of the ggrastr package from CRAN. This is the primary step before using any of its functionalities.

```r
install.packages("ggrastr")
```

--------------------------------

### Load ggrastr Package

Source: https://rdrr.io/cran/ggrastr

Load the ggrastr package into your R session to access its functions. This is typically done after installation.

```r
library(ggrastr)
```

--------------------------------

### Apply theme_pdf to a ggplot

Source: https://rdrr.io/cran/ggrastr/man/theme_pdf.html

Demonstrates how to apply the theme_pdf function to a ggplot object. This example creates a scatter plot and then applies the custom theme, disabling ticks and setting the legend position.

```R
library(ggplot2)
library(ggrastr)

data = rnorm(100)
colors = (1:100/100)
ggplot() + geom_point(aes(x=data, y=data, color=colors)) + theme_pdf(FALSE, legend.pos=c(1, 1))
```

--------------------------------

### Access ggrastr Help

Source: https://rdrr.io/cran/ggrastr

Access the main help documentation for the ggrastr package. This is useful for understanding the package's overall purpose and functions.

```r
help(ggrastr)
```

--------------------------------

### Scale raster objects with scale=1 (default)

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Demonstrates the default scaling behavior where rasterized objects maintain their original size (scale=1).

```r
# unchanged scaling, scale=1
plot <- ggplot(diamonds, aes(carat, price, colour = cut))
plot + rasterise(geom_point(), dpi = 300, scale = 1)

```

--------------------------------

### Select ragg_png rendering device

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Renders plots using the ragg_png device to work around alpha blending issues in the standard ragg device. Requires writing a temporary file.

```r
# Using 'ragg_png' solves the alpha blend, but requires writing a temporary file to disk
plot + rasterise(geom_point(), dpi = 5, dev = "ragg_png")

```

--------------------------------

### Set ggrastr.default.dpi with options()

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Set the default DPI for rasterization using options(). This affects subsequent rasterized plots unless overridden. Ensure to reset to default if needed.

```R
options(ggrastr.default.dpi=750)
```

```R
plot <- ggplot(diamonds, aes(carat, price, colour = cut))
new_plot = plot + rasterise(geom_point()) + theme(aspect.ratio = 1)
print(new_plot)
```

```R
options(ggrastr.default.dpi=300)
```

--------------------------------

### Set knitr chunk options

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Sets default options for knitr code chunks, ensuring code output is collapsed and comments are prefixed with '#>'.

```r
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

```

--------------------------------

### Set default DPI globally

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Sets a global default DPI for rasterization using options(), simplifying repeated calls with the same resolution. Plots will render at 750 DPI after this option is set.

```r
# Set the parameter 'dpi' globally with options(ggrastr.default.dpi=N)
The parameter `dpi` is an integer which sets the desired resolution in dots per inch. With ggrastr versions `>=0.2.2`, users can set this parameter globally, using options(). In the following example, plots will be rendered with `dpi=750` after the user sets this with `options(ggrastr.default.dpi=750)`:

```

--------------------------------

### Select Cairo rendering device

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Renders plots using the Cairo device, the default for ggrastr. Useful for comparing rendering quality with other devices.

```r
# The default 'cairo' at dpi=5
plot + rasterise(geom_point(), dpi = 5, dev = "cairo")

```

--------------------------------

### Select ragg rendering device

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Renders plots using the ragg device, which may offer faster performance and better anti-aliasing. Note potential alpha blending quirks.

```r
# Using 'ragg' gives better anti-aliasing but has unexpected alpha blending
plot + rasterise(geom_point(), dpi = 5, dev = "ragg")

```

--------------------------------

### theme_pdf

Source: https://rdrr.io/cran/ggrastr/man/theme_pdf.html

Applies a pretty theme to ggplot2 plots. This theme can be customized to show or hide ticks and to position the legend.

```APIDOC
## theme_pdf

### Description
Pretty theme 

### Usage
```R
theme_pdf(show.ticks = TRUE, legend.pos = NULL)
```

### Arguments
`show.ticks` |  boolean Whether to show x- and y-ticks (default=TRUE).  
`legend.pos` |  Vector with x and y position of the legend (default=NULL).  

### Value
ggplot2 with plot ticks and positioned legend 

### Examples
```R
library(ggplot2)
library(ggrastr)

data = rnorm(100)
colors = (1:100/100)
ggplot() + geom_point(aes(x=data, y=data, color=colors)) + theme_pdf(FALSE, legend.pos=c(1, 1))
```
```

--------------------------------

### Scale raster objects with scale < 1

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Decreases the size of rasterized objects by setting the 'scale' parameter to a value less than 1. 'scale=0.5' halves the size.

```r
# smaller objects, scale < 1
plot <- ggplot(diamonds, aes(carat, price, colour = cut))
plot + rasterise(geom_point(), dpi = 300, scale = 0.5)

```

--------------------------------

### Scale raster objects with scale > 1

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Increases the size of rasterized objects by setting the 'scale' parameter to a value greater than 1. 'scale=2' doubles the size.

```r
# larger objects, scale > 1
plot <- ggplot(diamonds, aes(carat, price, colour = cut))
plot + rasterise(geom_point(), dpi = 300, scale = 2)

```

--------------------------------

### Rasterize plots with facets

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Ensures that facets are rendered correctly without distorting points, maintaining their original shape and position relative to the facet grid.

```r
# Facets will not warp/distort points
set.seed(123)
plot + rasterise(geom_point(), dpi = 300) + facet_wrap(~ sample(1:3, nrow(diamonds), 2))

```

--------------------------------

### Maintain object shape with aspect ratio changes

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Demonstrates that rasterized points remain round even when the plot's aspect ratio is distorted. Ensures visual integrity of geometric shapes.

```r
# Points remain round across different aspect ratios
plot <- ggplot(diamonds, aes(carat, price, colour = cut))
plot + rasterise(geom_point(), dpi = 72) + theme(aspect.ratio = 0.2)

```

--------------------------------

### Rasterize multiple layers using lists

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Rasterizes multiple ggplot layers simultaneously using a list structure, particularly useful for complex geoms like geom_sf.

```r
world1 <- sf::st_as_sf(maps::map('world', plot = FALSE, fill = TRUE))
ggplot() + rasterise(
  list(
    list(
      geom_sf(data = world1),
      theme(panel.background = element_rect(fill = "skyblue"))
    ),
    list(
      list(
        geom_point(aes(x = rnorm(100, sd = 10), y = rnorm(100, sd = 10)))
      ),
      theme(panel.border = element_rect(fill = NA, colour = "blue"))
    )
  )
)

```

--------------------------------

### theme_pdf Function Definition

Source: https://rdrr.io/cran/ggrastr/man/theme_pdf.html

Defines the theme_pdf function for ggplot2 plots. It accepts arguments to control the visibility of ticks and the position of the legend.

```R
theme_pdf(show.ticks = TRUE, legend.pos = NULL)
```

--------------------------------

### Rasterize entire ggplot object

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Applies rasterization to a specified layer type within a ggplot object. Use 'layers' to target specific geoms like 'Point'.

```r
library(ggplot2)
library(ggrastr)

plot <- ggplot(diamonds, aes(carat, price, colour = cut)) +
  geom_point()

rasterize(plot, layers='Point', dpi=50)

```

--------------------------------

### Rasterize individual ggplot layers

Source: https://rdrr.io/cran/ggrastr/f/vignettes/Raster_geoms.md

Rasterizes a specific geom layer within a ggplot object, allowing other layers to remain in vector format. Useful for selectively optimizing plot elements.

```r
ggplot() +
  rasterise(geom_point(aes(carat, price, colour = cut), data=diamonds), dpi=30) +
  geom_point(aes(x=runif(20, 0, 5), y=runif(20, 0, 20000)), size=10, color="black", shape=8)

```
Tokens:
Raw