d3.polygonLength(polygon) <> Returns the length of the perimeter of the specified polygon.

d3.precisionFixed(step) Returns a suggested decimal precision for fixed point notation given the specified numeric step value. The step represents the minimum absolute difference between values that will be formatted. (This assumes that the values to be formatted are also multiples of step.) For example, given the numbers 1, 1.5, and 2, the step should be 0.5 and the suggested precision is 1: var p = d3.precisionFixed(0.5), f = d3.format("." + p + "f"); f(1); // "1.0" f(1.5); // "1.5" f

d3.pie() Constructs a new pie generator with the default settings.

d3.permute(array, indexes) Returns a permutation of the specified array using the specified array of indexes. The returned array contains the corresponding element in array for each index in indexes, in order. For example, permute(["a", "b", "c"], [1, 2, 0]) returns ["b", "c", "a"]. It is acceptable for the array of indexes to be a different length from the array of elements, and for indexes to be duplicated or omitted. This method can also be used to extract the values from an object into an

d3.partition() Creates a new partition layout with the default settings.

d3.pairs(array) For each adjacent pair of elements in the specified array, returns a new array of tuples of element i and element i - 1. For example: d3.pairs([1, 2, 3, 4]); // returns [[1, 2], [2, 3], [3, 4]] If the specified array has fewer than two elements, returns the empty array.

d3.path() Constructs a new path serializer that implements CanvasPathMethods.

d3.namespaces The map of registered namespace prefixes. The initial value is: { svg: "http://www.w3.org/2000/svg", xhtml: "http://www.w3.org/1999/xhtml", xlink: "http://www.w3.org/1999/xlink", xml: "http://www.w3.org/XML/1998/namespace", xmlns: "http://www.w3.org/2000/xmlns/" } Additional prefixes may be assigned as needed to create elements or attributes in other namespaces.

d3.nest() Creates a new nest operator. The set of keys is initially empty.

d3.packSiblings(circles) Packs the specified array of circles, each of which must have a circle.r property specifying the circle’s radius. Assigns the following properties to each circle: circle.x - the x-coordinate of the circle’s center circle.y - the y-coordinate of the circle’s center The circles are positioned according to the front-chain packing algorithm by Wang et al.