d3.curveCatmullRomClosed(context)

d3.curveMonotoneX(context)

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

d3.curveBundle(context)

d3.symbolTriangle The up-pointing triangle symbol type.

d3.curveMonotoneY(context)

d3.symbolSquare The square symbol type.

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

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

pie.value([value]) If value is specified, sets the value accessor to the specified function or number and returns