scatter plot with colorAxis

[slowkow]

Can I use a color scale with scatter plots?

Your comment on this Stackoverflow question suggests it is not possible:

This is a highchartsjs restriction, by now, you can't use or put a colorAxis in a scatter plot on highcharts – jbkunst May 19 '17 at 14:55

The related issue #317 has a hack that suggests this might be possible.

Here's my plot:

library(highcharter)

hchart(mtcars, "scatter", hcaes(x = wt, y = mpg, color = qsec)) %>%
  hc_colorAxis()

There are two problems:

1. The colors in the scale do not match the colors of the points.
2. The color scale does not have tick marks.

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By the way, thank you for your fantastic work! Your package is a valuable contribution for the R community. 👍

[slowkow]

Paweł Fus posted this fiddle in a related Stackoverflow post. He modified the pie chart to include a color scale.

This might be a good starting point to learn how to make a proper color scale for scatter plots.

http://jsfiddle.net/w9nuha8n/4/

[slowkow]

I hacked the Stackoverflow code to make a colorbar for a scatter plot.

https://gist.github.com/slowkow/2734989182ea46e3a0a8a7299c2e25f9

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It looks like this file might be a good place to start hacking:

https://github.com/jbkunst/highcharter/blob/master/R/helpers.R#L302-L310

I'll post an update if I make any progress on this...

[jbkunst]

Hey @slowkow ,

Thanks so much to come up with this. This is a really nice missing feature. I'm checking the jsfiddle and your gist and it's seems easy to implement if we include as a custm script.

Thanks again!

[slowkow]

Great! Once you have some code, I'll be happy to test it.

Ideally, I would expect highcharter to automatically mimic ggplot2, so something like this would happen:

if (is.numeric(color) || is.integer(color)) {
    # make colorbar
} else if (is.factor(color) || is.character(color)) {
    # make legend with colors for each level
}

Excited to see what you come up with! 😄