d3.interpolateObject(a, b) Returns an interpolator between the two objects a and b. Internally, an

d3.interpolateBasis(values) Returns a uniform nonrational B-spline interpolator through the specified array of values

d3.interpolateHslLong(a, b)

d3.interpolateCubehelixLong(a, b)

d3.interpolateRgb(a, b)

interpolate.gamma(gamma) Given that interpolate is one of

d3.interpolateHcl(a, b)

d3.interpolateRound(a, b) Returns an interpolator between the two numbers a and b; the interpolator

d3.interpolateRgbBasisClosed(colors) Returns a uniform nonrational B-spline interpolator through the specified array of colors

d3.interpolateHsl(a, b)