Scatterplot: allow continuous overlay variables (needs to optionally support gradient colormaps)

[d-callan]

mbio beta diversity app will need a scatterplot w a gradient colormap. but i dont think (@danicahelb could confirm) that clinepi wants gradient colormaps? so our scatter viz needs to be able to support them, but also have them be optional.

my (possibly flawed) memory from ann is that the components necessary to build a gradient colormap are available in web-components, but i havent yet confirmed.

[danicahelb]

clinepi would be happy to use gradient colormaps to allow continuous vars to be used as the overlay on scatter plots

[danicahelb]

prioritize for immediately following b60 release since mbio needs this for beta div

[bobular]

@d-callan - are we envisaging always using binning for continuous overlay vars?

[d-callan]

nope. its a true gradient

[d-callan]

an ex of the goal, though w our own color palette(s). id imagine to start w have a diverging one like in the ex above that is applied if the metadata indicates the range crosses 0, and one thats not. it wont be perfect but gets us a decent start.

[d-callan]

also see #306 for prev thinking

[d-callan]

id also be fine to leave numbers w <9 values using a categorical palette for now if we dont want to tack on discretizing one of our continuous palettes dynamically yet. can make that a separate issue.

[bobular]

Thanks for the extra info. I see Ann did a lot, but it would likely be a challenge to merge the client work now. Good for reference though.

Is the back end (plot.data) ready to go for continuous (unbinned) overlay, but the constraints for the passthrough scatterplot app do not allow it? Connor will be looking into this. I guess while testing he can spoof or ignore the constraints temporarily?

[d-callan]

Yea plot.data is ready, and I can get constraints in the data service on a branch somewhere without too much of a headache I think. @chowington when do you need that by?

[chowington]

I haven't gotten anything spun up yet---still soaking up previous work, so no rush!

[chowington]

@d-callan I might be ready to start testing this by tomorrow, FYI!

[d-callan]

@chowington see VEuPathDB/EdaDataService#138