Wednesday, October 23, 2019

Updated prototype Ishihara color detection test R package & new app

This morning I worked on developing a prototype web application for the Ishira color perception test based on R & the shiny web application framework.

To do this I had to make some small updates to my very basic (so far) R package ishihara.

The first of these involved identifying the pattern-forming circles in the one Ishihara plate that I'd digitized (plate 2, I believe).

Unfortunately, this was not as straightforward as it seems as I myself am abnormally trichromatic so I can't actually see the pattern & had to ask for help.

Here's my helper at work:

The result is now that the pattern can now be visualized by even a colorblind person by applying a transparency filter to the non pattern-forming circles.

This is what I mean:

library(ishihara)
## 
##    *************************************************
##    *                                               *
##    *    This package is just for fun & is not a    *
##    *           medical diagnostic tool.            *
##    *                                               *
##    ***********************************************
data(plate2)
plot(plate2) ## normal

plot of chunk unnamed-chunk-1

plot(plate2,alpha=0.2) ## 80% transparent

plot of chunk unnamed-chunk-1

Users can even create a neat animation where transparency is faded on & off. Try it:

for(i in 50:0){
    plot(plate2,alpha=min(1,i/50))
    Sys.sleep(0.1)
}
for(i in 1:50){
    plot(plate2,alpha=min(1,i/50))
    Sys.sleep(0.1)
}

Check out the app and let me know what you think!