arc.cornerRadius([radius]) If radius is specified, sets the corner radius to the specified function or number and returns this arc generator. If radius is not specified, returns the current corner radius accessor, which defaults to: function cornerRadius() { return 0; } If the corner radius is greater than zero, the corners of the arc are rounded using circles of the given radius. For a circular sector, the two outer corners are rounded; for an annular sector, all four corners are rounded.

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.pointRadius([radius]) If radius is specified, sets the radius used to display Point and MultiPoint features to the specified number. If radius is not specified, returns the current radius accessor, which defaults to 4.5. While the radius is commonly specified as a number constant, it may also be specified as a function which is computed per feature, being passed the any arguments passed to the path generator. For example, if your GeoJSON data has additional properties, you might access

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.

transform.rescaleX(x) Returns a copy of the continuous scale x whose domain is transformed. This is implemented by first applying the inverse x-transform on the scale’s range, and then applying the inverse scale to compute the corresponding domain: function rescaleX(x) { var range = x.range().map(transform.invertX, transform), domain = range.map(x.invert, x); return x.copy().domain(domain); } The scale x must use d3.interpolateNumber; do not use continuous.rangeRound as this reduce

time.ticks([count]) time.ticks([interval]) Returns representative dates from the scale’s domain. The returned tick values are uniformly-spaced (mostly), have sensible values (such as every day at midnight), and are guaranteed to be within the extent of the domain. Ticks are often used to display reference lines, or tick marks, in conjunction with the visualized data. An optional count may be specified to affect how many ticks are generated. If count is not specified, it defaults to 10. The sp

d3.geoTransverseMercator() d3.geoTransverseMercatorRaw The transverse spherical Mercator projection. Defines a default projection.clipExtent such that the world is projected to a square, clipped to approximately ±85° latitude.

d3.geoDistance(a, b) Returns the great-arc distance in radians between the two points a and b. Each point must be specified as a two-element array [longitude, latitude] in degrees.

point(value) Given a value in the input domain, returns the corresponding point derived from the output range. If the given value is not in the scale’s domain, returns undefined.