PieChart

PieChart[{y₁,y₂,…}]

makes a pie chart with sector angle proportional to y₁, y₂, … .

PieChart[{…,w_i[y_i,…],…,w_j[y_j,…],…}]

makes a pie chart with sector features defined by the symbolic wrappers w_k.

PieChart[{data₁,data₂,…}]

makes a pie chart from multiple datasets data_i.

Details and Options

	y_i	a pure sector value
	Quantity[y_i,unit]	sector value with a unit
	w_i[y_i,…]	a sector with value y_i and wrapper w_i
	form_i->m_i	a sector form with metadata m_i

	{e₁,e₂,…}	list of elements with or without wrappers
	<\|k₁y₁,k₂y₂,…\|>	association of keys and values
	TimeSeries[…],EventSeries[…],TemporalData[…]	time series, event series, and temporal data
	WeightedData[…],EventData[…]	augmented datasets
	w[{e₁,e₂,…},…]	wrapper applied to a whole dataset
	w[{data₁,data₁,…},…]	wrapper applied to all datasets

	Annotation[e,label]	provide an annotation
	Button[e,action]	define an action to execute when the element is clicked
	Callout[e,label]	display the element with a callout
	EventHandler[e,…]	define a general event handler for the element
	Hyperlink[e,uri]	make the element act as a hyperlink
	Labeled[e,…]	display the element with labeling
	Legended[e,…]	include features of the element in a chart legend
	Mouseover[e,over]	make the element show a mouseover form
	PopupWindow[e,cont]	attach a popup window to the element
	StatusArea[e,label]	display in the status area when the element is moused over
	Style[e,opts]	show the element using the specified styles
	Tooltip[e,label]	attach an arbitrary tooltip to the element

	"RadialOuter","RadialCenter","RadialInner"	positions within sectors
	"RadialOutside","RadialInside","RadialEdge"	positions outside sectors
	"RadialCallout", "VerticalCallout"	positions with callout lines
	{{s_θ,s_r},{l_x,l_y}}	scaled position {l_x,l_y} in the label at scaled polar position {s_θ,s_r} in the sector

	Automatic	automatic placement
	{x,y}	position in the graphic
	Scaled[{s_θ,s_r}]	scaled polar position {s_θ,s_r} in the sector
	{pos,{l_x,l_y}}	scaled position {l_x,l_y} in the label at position pos

PieChart has the same options as Graphics with the following additions and changes:

ChartBaseStyle	Automatic	overall style for sectors
ChartElementFunction	Automatic	how to generate raw graphics for sectors
ChartLabels	None	labels for data elements and datasets
ChartLayout	Automatic	overall layout to use
ChartLegends	None	legends for data elements and datasets
ChartStyle	Automatic	style for sector
ColorFunction	Automatic	how to color sectors
ColorFunctionScaling	True	whether to normalize arguments to ColorFunction
LabelingFunction	Automatic	how to label sectors
LegendAppearance	Automatic	overall appearance of legends
PerformanceGoal	$PerformanceGoal	aspects of performance to try to optimize
PlotRange	Automatic	range of values to include
PlotTheme	$PlotTheme	overall theme for the chart
PolarAxes	False	whether to draw polar axes
PolarAxesOrigin	Automatic	where to draw polar axes
PolarGridLines	None	polar gridlines to draw
PolarTicks	Automatic	polar axes ticks
SectorOrigin	Automatic	initial angle and radius of sectors
SectorSpacing	Automatic	spacing between sectors
TargetUnits	Automatic	units to display in the chart

Possible settings for ChartLayout include "Grouped" and "Stacked".
The arguments supplied to ChartElementFunction are the sector region {{θ_min,θ_max},{r_min,r_max}}, the values y_i, and the metadata {m₁,m₂,…} from each level in a nested list of datasets.
A list of built-in settings for ChartElementFunction can be obtained from ChartElementData["PieChart"].
The argument supplied to ColorFunction is y_i.
Style and other specifications from options and other constructs in PieChart are effectively applied in the order ChartStyle, ColorFunction, Style and other wrappers, and ChartElementFunction, with later specifications overriding earlier ones.