d3.timeYear d3.utcYear Years (e.g., January 1, 2012 at 12:00 AM); ranges from 365 to 366 days.

node.leaves() Returns the array of leaf nodes in traversal order; leaves are nodes with no children.

d3.easeElasticInOut(t) Symmetric elastic easing; scales elasticIn for t in [0, 0.5] and elasticOut for t in [0.5, 1].

d3.easeCubic(t) d3.easeCubicInOut(t) Symmetric cubic easing; scales cubicIn for t in [0, 0.5] and cubicOut for t in [0.5, 1]. Also equivalent to poly.exponent(3).

d3.forceCenter([x, y]) Creates a new centering force with the specified x- and y- coordinates. If x and y are not specified, they default to ⟨0,0⟩.

time.rangeRound([range]) See continuous.rangeRound.

area.lineX1() Returns a new line generator that has this area generator’s current defined accessor, curve and context. The line’s x-accessor is this area’s x1-accessor, and the line’s y-accessor is this area’s y0-accessor.

tree.nodeSize([size]) If size is specified, sets this tree layout’s node size to the specified two-element array of numbers [width, height] and returns this tree layout. If size is not specified, returns the current node size, which defaults to null. A node size of null indicates that a layout size will be used instead. When a node size is specified, the root node is always positioned at ⟨0, 0⟩.

d3.curveCatmullRomClosed(context) Produces a closed cubic Catmull–Rom spline using the specified control points and the parameter alpha, which defaults to 0.5, as proposed by Yuksel et al. When a line segment ends, the first three control points are repeated, producing a closed loop.

line(data) Generates a line for the given array of data. Depending on this line generator’s associated curve, the given input data may need to be sorted by x-value before being passed to the line generator. If the line generator has a context, then the line is rendered to this context as a sequence of path method calls and this function returns void. Otherwise, a path data string is returned.