d3.geoBottomley() d3.geoBottomleyRaw(sinPsi) The Bottomley projection “draws lines of latitude as concentric circular arcs, with arc lengths equal to their lengths on the globe, and placed symmetrically and equally spaced across the vertical central meridian.”

d3.geoHammer() d3.geoHammerRaw(A, B) The Hammer projection. Depending the chosen coefficient and aspect, also known as Eckert–Greifendorff, quartic authalic, and Briesemeister.

force(alpha) Applies this force, optionally observing the specified alpha. Typically, the force is applied to the array of nodes previously passed to force.initialize, however, some forces may apply to a subset of nodes, or behave differently. For example, d3.forceLink applies to the source and target of each link.

selection.call(function[, arguments…]) Invokes the specified function exactly once, passing in this selection along with any optional arguments. Returns this selection. This is equivalent to invoking the function by hand but facilitates method chaining. For example, to set several styles in a reusable function: function name(selection, first, last) { selection .attr("first-name", first) .attr("last-name", last); } Now say: d3.selectAll("div").call(name, "John", "Snow"); This is

map.size() Returns the number of entries in this map.

d3.schemeCategory20c An array of twenty categorical colors represented as RGB hexadecimal strings. This color scale includes color specifications and designs developed by Cynthia Brewer (colorbrewer2.org).

local.get(node) Returns the value of this local on the specified node. If the node does not define this local, returns the value from the nearest ancestor that defines it. Returns undefined if no ancestor defines this local.

link.links([links]) If links is specified, sets the array of links associated with this force, recomputes the distance and strength parameters for each link, and returns this force. If links is not specified, returns the current array of links, which defaults to the empty array. Each link is an object with the following properties: source - the link’s source node; see simulation.nodes target - the link’s target node; see simulation.nodes index - the zero-based index into links, assigned

transition.selection() Returns the selection corresponding to this transition.

d3.geoAiry() d3.geoAiryRaw(beta) Airy’s minimum-error azimuthal projection.