In njtierney/ishihara: What the Package Does (One Line, Title Case)

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "man/figures/README-",
  out.width = "100%"
)

ishihara

The goal of ishihara is to create an Ishihara test, which can help assess colourblindness.

There are a few implementations of this test around the web, but I haven't seen one that worked for R, so here is my crack at implementing it.

Note that this is a work in progress, don't use it for proper testing.

Installation

The development version from GitHub with:

# install.packages("devtools")
devtools::install_github("njtierney/ishihara")

Proof of Concept

I had an idea on how I could maybe create this kind of figure in R, using spatial tools. The general process is:

1. Create a bunch of circles with packcircles
2. Convert that to an SF object
3. Pull in a vector font from gridfont
4. Convert that font into an SF object
5. Overlay the two SF objects and see where they intersect
6. Plot the circles that are intersected by the text
7. Change the colour palette in ggplot2 to see the impact of colourblindness

library(ishihara)
## basic example code
library(ggplot2)

I'm still working through the details of the implementation and usability, but the general idea is to create something like this:

set.seed(2020-05-10)
cb_1 <- ishihara_data("1")
gg_ishihara <- gg_ishihara(cb_1)
gg_ishihara
gg_ishihara + scale_fill_brewer(palette = "Dark2")
gg_ishihara + scale_fill_viridis_d()
gg_ishihara + scale_fill_manual(values = c("black", "grey90"))
gg_ishihara + scale_fill_manual(values = c("red", "green"))

njtierney/ishihara documentation built on May 31, 2020, 9:01 a.m.