d3.interpolateCool(t) Given a number t in the range [0,1], returns the corresponding color from Niccoli’s perceptual rainbow, represented as an RGB string.

d3.interpolateViridis(t) Given a number t in the range [0,1], returns the corresponding color from the “viridis” perceptually-uniform color scheme designed by van der Walt, Smith and Firing for matplotlib, represented as an RGB string.

d3.geoFahey() d3.geoFaheyRaw The Fahey pseudocylindrical projection.

selection.text([value]) If a value is specified, sets the text content to the specified value on all selected elements, replacing any existing child elements. If the value is a constant, then all elements are given the same text content; otherwise, if the value is a function, then the function is evaluated for each selected element, in order, being passed the current datum (d), the current index (i), and the current group (nodes), with this as the current DOM element. The function’s return v

d3.polygonLength(polygon) <> Returns the length of the perimeter of the specified polygon.

catmullRom.alpha(alpha) Returns a cubic Catmull–Rom curve with the specified alpha in the range [0, 1]. If alpha is zero, produces a uniform spline, equivalent to curveCardinal with a tension of zero; if alpha is one, produces a chordal spline; if alpha is 0.5, produces a centripetal spline. Centripetal splines are recommended to avoid self-intersections and overshoot. For example: var line = d3.line().curve(d3.curveCatmullRom.alpha(0.5));

point.bandwidth() Returns zero.

d3.timeDay d3.utcDay Days (e.g., February 7, 2012 at 12:00 AM); typically 24 hours. Days in local time may range from 23 to 25 hours due to daylight saving.

d3.chord() Constructs a new chord layout with the default settings.

d3.interpolateBasisClosed(values) Returns a uniform nonrational B-spline interpolator through the specified array of values, which must be numbers. The control points are implicitly repeated such that the resulting one-dimensional spline has cyclical C² continuity when repeated around t in [0,1]. See also d3.curveBasisClosed.