stack.order([order]) If order is specified, sets the order accessor to the specified function or array and

area.y([y]) If y is specified, sets y0

symbol.size([size]) If size is specified, sets the size to the specified function or number and returns this

d3.curveStepBefore(context)

line.y([y]) If y is specified, sets the y accessor to the specified function or number and returns this line

d3.symbolStar The pentagonal star (pentagram) symbol type.

d3.curveStep(context)

radialArea(data) Equivalent to area.

radialLine.context([context]) Equivalent to

area.x0([x]) If x is specified, sets the x0 accessor to the specified function or number and returns this area