https://teunbrand.github.io/ggchromatic/

Colour and fill scales for 'ggplot2' using colour spaces.
https://teunbrand.github.io/ggchromatic/

colors ggplot-extension ggplot2 ggplot2-scales

Last synced: about 2 months ago
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Colour and fill scales for 'ggplot2' using colour spaces.

• Host: GitHub
• URL: https://teunbrand.github.io/ggchromatic/
• Owner: teunbrand
• License: other
• Created: 2021-01-14T17:23:34.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2021-02-24T21:56:59.000Z (over 3 years ago)
• Last Synced: 2024-07-17T06:42:03.382Z (2 months ago)
• Topics: colors, ggplot-extension, ggplot2, ggplot2-scales
• Language: R
• Homepage: https://teunbrand.github.io/ggchromatic/
• Size: 2.25 MB
• Stars: 9
• Watchers: 3
• Forks: 1
• Open Issues: 6
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE

Awesome Lists containing this project

README

        
---

output: github_document

---

```{r, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "man/figures/README-",

  out.width = "100%"

)

```

# ggchromatic 

*/ʤiː-ʤiːkrəʊˈmætɪk/*

[![Lifecycle: experimental](https://img.shields.io/badge/lifecycle-experimental-orange.svg)](https://www.tidyverse.org/lifecycle/#experimental)

[![R-CMD-check](https://github.com/teunbrand/ggchromatic/workflows/R-CMD-check/badge.svg)](https://github.com/teunbrand/ggchromatic/actions)

[![Codecov test coverage](https://codecov.io/gh/teunbrand/ggchromatic/branch/master/graph/badge.svg)](https://codecov.io/gh/teunbrand/ggchromatic?branch=master)

The 'ggchromatic' package provides additional colour and fill scales to use with 'ggplot2' It uses the 'ggplot2' extension system to map a number of variables to different colour spaces with the 'farver' package. The package introduces 'chromatic scales', a term mirroring music terms. In music, chromatic scales cover all 12 notes. In ggchromatic, a chromatic scale can cover all channels in colour space. Admittedly, colour spaces might not be the most intuitive tool for interpreting a data visualisation, but can be useful for visualising less strict data impressions.

## Installation

You can install the development of ggchromatic version from [GitHub](https://github.com/) with:

``` r

# install.packages("devtools")

devtools::install_github("teunbrand/ggchromatic")

```

## Example

These is a basic example of mapping three variables to the RGB colour space. This happens automatically for colours constructed by `rgb_spec()`.

```{r}

library(ggchromatic)

ggplot(mtcars, aes(mpg, disp)) +

  geom_point(aes(colour = cmy_spec(mpg, drat, wt)))

```

The associated scale functions give more options for customisation, like the HSV scale below.

```{r}

df <- data.frame(

  x = c(row(volcano)), y = c(col(volcano)), z = c(volcano)

)

ggplot(df, aes(x, y, fill = hsv_spec(z, x, y))) +

  geom_raster() +

  scale_fill_hsv(limits = list(h = c(NA, 170)),

                 oob = scales::oob_squish,

                 channel_limits = list(h = c(0, 0.8))) +

  coord_equal()

```

Perhaps a use-case for chromatic scales is when the interpretation of a variable isn't directly related to a property of the data points. For example, embeddings project data into a new space which might preserve some properties, such as distance between data points, but wherein dimensions of the new space are meaningless on their own. You can use a chromatic scale to map the embedding to colours, which can give a neat 'flavour' to the data points through colour.

```{r}

if (requireNamespace("umap")) {

  set.seed(42)

  # Project the iris dataset into 3D UMAP space

  config <- umap::umap.defaults

  config$n_components <- 3

  umap_3d <- umap::umap(iris[, 1:4], config)$layout

  

  df <- data.frame(

    SL = iris$Sepal.Length,

    SW = iris$Petal.Width,

    x = umap_3d[, 1],

    y = umap_3d[, 2],

    z = umap_3d[, 3]

  )

  

  ggplot(df, aes(SL, SW)) +

    geom_point(aes(colour = rgb_spec(x, y, z)))

}

```