node.eachBefore(function) Invokes the specified function for node and each descendant in pre-order traversal, such that a given node is only visited after all of its ancestors have already been visited. The specified function is passed the current node.

d3.geoHammerRetroazimuthal() d3.geoHammerRetroazimuthalRaw(phi0) The Hammer retroazimuthal projection. Note: requires clipping to the sphere.

d3.symbolSquare The square symbol type.

d3.geoBonne() d3.geoBonneRaw(phi0) The Bonne pseudoconical equal-area projection. The Werner projection is a limiting form of the Bonne projection with a standard parallel at ±90°. The default center assumes the default parallel of 45° and should be changed if a different parallel is used.

tile.extent([extent]) If extent is specified, sets this tile layout’s extent to the specified array of points [[x0, y0], [x1, y1]], where [x0, y0] is the top-left corner and [x1, y1] is the bottom-right corner, and returns this tile layout. If extent is not specified, returns the current layout extent.

d3.interpolatePuBu(t) d3.schemePuBu Given a number t in the range [0,1], returns the corresponding color from the “PuBu” sequential color scheme represented as an RGB string.

d3.geoBoggs() d3.geoBoggsRaw The Boggs eumorphic projection. More commonly used in interrupted form.

treemap.paddingTop([padding]) If padding is specified, sets the top padding to the specified number or function and returns this treemap layout. If padding is not specified, returns the current top padding function, which defaults to the constant zero. If padding is a function, it is invoked for each node with children, being passed the current node. The top padding is used to separate the top edge of a node from its children.

conic.parallels([parallels]) The two standard parallels that define the map layout in conic projections.

area.y([y]) If y is specified, sets y0 to y and y1 to null and returns this area generator. If y is not specified, returns the current y0 accessor.