node.links() Returns an array of links for this node, where each link is an object that defines source and target properties. The source of each link is the parent node, and the target is a child node.

transition.ease([value]) Specifies the transition easing function for all selected elements. The value must be specified as a function. The easing function is invoked for each frame of the animation, being passed the normalized time t in the range [0, 1]; it must then return the eased time tʹ which is typically also in the range [0, 1]. A good easing function should return 0 if t = 0 and 1 if t = 1. If an easing function is not specified, it defaults to d3.easeCubic. If a value is not specif

transition.delay([value]) For each selected element, sets the transition delay to the specified value in milliseconds. The value may be specified either as a constant or a function. If a function, it is immediately evaluated for each selected element, in order, being passed the current datum d and index i, with the this context as the current DOM element. The function’s return value is then used to set each element’s transition delay. If a delay is not specified, it defaults to zero. If a va

path.centroid(object) Returns the projected planar centroid (typically in pixels) for the specified GeoJSON object. This is handy for, say, labeling state or county boundaries, or displaying a symbol map. For example, a noncontiguous cartogram might scale each state around its centroid. This method observes any clipping performed by the projection; see projection.clipAngle and projection.clipExtent.

quantize.invertExtent(value) Returns the extent of values in the domain [x0, x1] for the corresponding value in the range: the inverse of quantize. This method is useful for interaction, say to determine the value in the domain that corresponds to the pixel location under the mouse. var width = d3.scaleQuantize() .domain([10, 100]) .range([1, 2, 4]); width.invertExtent(2); // [40, 70]

d3.treemapSlice(node, x0, y0, x1, y1) Divides the rectangular area specified by x0, y0, x1, y1 vertically according the value of each of the specified node’s children. The children are positioned in order, starting with the top edge (y0) of the given rectangle. If the sum of the children’s values is less than the specified node’s value (i.e., if the specified node has a non-zero internal value), the remaining empty space will be positioned on the bottom edge (y1) of the given rectangle.

drag.subject([subject]) If subject is specified, sets the subject accessor to the specified object or function and returns the drag behavior. If subject is not specified, returns the current subject accessor, which defaults to: function subject(d) { return d == null ? {x: event.x, y: event.y} : d; } The subject of a drag gesture represents the thing being dragged. It is computed when an initiating input event is received, such as a mousedown or touchstart, immediately before the drag gestu

treemap(root) Lays out the specified root hierarchy, assigning the following properties on root and its descendants: node.x0 - the left edge of the rectangle node.y0 - the top edge of the rectangle node.x1 - the right edge of the rectangle node.y1 - the bottom edge of the rectangle You must call root.sum before passing the hierarchy to the treemap layout. You probably also want to call root.sort to order the hierarchy before computing the layout.

axis.tickArguments([arguments]) If arguments are specified, sets the arguments that will be passed to scale.ticks and scale.tickFormat when the axis is rendered, and returns the axis generator. The meaning of the arguments depends on the axis’ scale type: most commonly, the arguments are a suggested count for the number of ticks (or a time interval for time scales), and an optional format specifier to customize how the tick values are formatted. This method is a convenient alternative to set

selection.sort(compare) Returns a new selection that contains a copy of each group in this selection sorted according to the compare function. After sorting, re-inserts elements to match the resulting order (per selection.order). The compare function, which defaults to ascending, is passed two elements’ data a and b to compare. It should return either a negative, positive, or zero value. If negative, then a should be before b; if positive, then a should be after b; otherwise, a and b are con