d3.scaleQuantileP

[mbostock]

How about in addition to d3.scaleQuantile, which requires you to specify a range with q elements to compute q-quantiles, you also have d3.scaleQuantileP, whose range is continuous and defaults to [0, 1], computing the p-quantile of an input value from the domain.

And then you can specify an output interpolator, say d3.interpolateViridis, so that you can map the p-quantile of the input value to a color.

Though this is somewhat tricky because it’s not clear whether d3.scaleQuantileP should function more like a d3.scaleSequential that takes a fixed output interpolator, or d3.scaleLinear where you can specify both the range and the interpolator.

[mbostock]

This is closely related to #62 as implemented in @393b9a5: d3.scaleSequentialQuantile computes the p-quantile prior to applying the interpolator.

[mbostock]

As previously commented, I think d3.scaleSequentialQuantile covers this need.

If you want discrete quantiles, use d3.scaleQuantile:

color = d3.scaleQuantile().domain(values).range(d3.schemeBlues[9])

If you want continuous quantiles, use d3.scaleSequentialQuantile:

color = d3.scaleSequentialQuantile(d3.interpolateBlues).domain(values)