IMP: Add paired color palettes (scatterplot/lineplot)

[colinbrislawn]

When comparing two groups or dealing with paired samples, having paired color scheme is helpful!

Here are two legends from a Rescript graph where I want to use a paired palette!

Custom color palettes would also address this problem!

[colinbrislawn]

Vega color schemes: https://vega.github.io/vega/docs/schemes/#categorical

paired - from Cynthia Brewer's ColorBrewer
tableau20 - extends tableau10
category20 - extends category10

category20b and category20c offer quad channel maps, which is cool

[lizgehret]

Hey @colinbrislawn,

Thanks for this- can you provide some more context for exactly what you're hoping to see in those two examples you shared above? Are you hoping for a color scheme that contains pairs of two for both of those examples, or a different ordering? And I'm assuming this is for scatterplot and/or lineplot (based on the legend icons)?

For some context, I chose category10 for scatterplot and lineplot because this color scheme provides maximum contrast between groups, especially when the number of groupings is small. That being said, I can see it being useful to implement a color scheme dropdown with a few options (similar to what I have implemented in heatmap). We will be limited by the available color schemes in vega (since this is what all of these visualizations are rendered using), but it would definitely be doable to add in a paired and/or quad channel.

[colinbrislawn]

Sure! I made some plots with paired palettes with the Vega editor:
colinbrislawn/unite-train#17 (comment)

edit: better graph
Panel x. F-Measure varies across clustering levels with inclusion of singletons:
All three database clustering levels of 97% (blue), 99% (green), and dynamic (red) show decreasing F score at lower taxonomic ranks. Including singletons (darker) decreases F score compared to excluding singletons (lighter).

The grouping in colors reflects a grouping in my experimental design.

We will be limited by the available color schemes in vega

Sure! And it looks like Vega already supports a few.

When making these graphs, I also allowed the legend to be larger to show longer text. New issue?

[lizgehret]

Hey @colinbrislawn,

Thanks, these details are helpful! I'm happy to add a color scheme drop-down in scatterplot and lineplot with a few options to support viewing datasets like this.

When making these graphs, I also allowed the legend to be larger to show longer text. New issue?

Yes, that would be great- thanks!