simulation.alphaDecay([decay]) If decay is specified, sets the alpha decay rate to the specified number in the range [0,1] and returns this simulation. If decay is not specified, returns the current alpha decay rate, which defaults to 0.0228… = 1 - pow(0.001, 1 / 300) where 0.001 is the default minimum alpha. The alpha decay rate determines how quickly the current alpha interpolates towards the desired target alpha; since the default target alpha is zero, by default this controls how quickly

nest.sortValues(comparator) Sorts leaf elements using the specified comparator function, such as d3.ascending or d3.descending. This is roughly equivalent to sorting the input array before applying the nest operator; however it is typically more efficient as the size of each group is smaller. If no value comparator is specified, elements will be returned in the order they appeared in the input array. This applies to nest.map, nest.entries and nest.object.

d3.color(specifier) Parses the specified CSS Color Module Level 3 specifier string, returning an RGB or HSL color. If the specifier was not valid, null is returned. Some examples: rgb(255, 255, 255) rgb(10%, 20%, 30%) rgba(255, 255, 255, 0.4) rgba(10%, 20%, 30%, 0.4) hsl(120, 50%, 20%) hsla(120, 50%, 20%, 0.4) #ffeeaa #fea steelblue The list of supported named colors is specified by CSS. Note: this function may also be used with instanceof to test if an object is a color instance. The same

d3.symbolCircle The circle symbol type.

tree.separation([separation]) If separation is specified, sets the separation accessor to the specified function and returns this tree layout. If separation is not specified, returns the current separation accessor, which defaults to: function separation(a, b) { return a.parent == b.parent ? 1 : 2; } A variation that is more appropriate for radial layouts reduces the separation gap proportionally to the radius: function separation(a, b) { return (a.parent == b.parent ? 1 : 2) / a.depth;

d3.interpolateCubehelixLong(a, b) Or, with a gamma of 3.0 to emphasize high-intensity values: Like interpolateCubehelix, but does not use the shortest path between hues.

quadtree.y([y]) If y is specified, sets the current y-coordinate accessor and returns the quadtree. If y is not specified, returns the current y-accessor, which defaults to: function y(d) { return d[1]; } The y-acccessor is used to derive the y-coordinate of data when adding to and removing from the tree. It is also used when finding to re-access the coordinates of data previously added to the tree; therefore, the x- and y-accessors must be consistent, returning the same value given the sa

d3.quadtree([data[, x, y]]) Creates a new, empty quadtree with an empty extent and the default x- and y-accessors. If data is specified, adds the specified array of data to the quadtree. This is equivalent to: var tree = d3.quadtree() .addAll(data); If x and y are also specified, sets the x- and y- accessors to the specified functions before adding the specified array of data to the quadtree, equivalent to: var tree = d3.quadtree() .x(x) .y(y) .addAll(data);

arc.centroid(arguments…) Computes the midpoint [x, y] of the center line of the arc that would be generated by the given arguments. The arguments are arbitrary; they are simply propagated to the arc generator’s accessor functions along with the this object. To be consistent with the generated arc, the accessors must be deterministic, i.e., return the same value given the same arguments. The midpoint is defined as (startAngle + endAngle) / 2 and (innerRadius + outerRadius) / 2. For example:

selection.on(typenames[, listener[, capture]]) Adds or removes a listener to each selected element for the specified event typenames. The typenames is a string event type, such as click, mouseover, or submit; any DOM event type supported by your browser may be used. The type may be optionally followed by a period (.) and a name; the optional name allows multiple callbacks to be registered to receive events of the same type, such as click.foo and click.bar. To specify multiple typenames, sepa