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PolarArea

Creates a polar area chart (Nightingale rose or coxcomb) from an array of data: every category gets an equal slice of the circle, and each wedge’s radius shows its value. With a metric, each category stacks its groupBy groups outward from the center.

Basic example

Section titled “Basic example”

Every row gets an equal slice of the circle, and its wedge’s radius shows its value. The radius uses a square-root scale by default, so each wedge’s area — what the eye compares — stays proportional to its value. The labels around the circle name every wedge, so the legend steps aside.

Defines the mapping between data and shape. The value can be a String matching a key in each data point (default is "id"), or an accessor Function that returns a unique value for each data point. Additionally, an Array of these values may be provided if the visualization supports nested hierarchies.

Accessor for each row's value.

radialScale

How values map onto radii: "sqrt" (default) makes each wedge's area proportional to its value; "linear" makes its radius proportional.

Nightingale rose

Section titled “Nightingale rose”

With a metric, every metric value is one slice of the circle and its groupBy groups stack outward from the center — Florence Nightingale’s diagram of the causes of death in the Crimean War. The value rings sit on nice values and are labeled along levelLabelAngle.

The category each wedge belongs to. Rows sharing a metric share one slice of the circle, their groupBy groups stacked outward from the center in data order. Unset, every row is its own category.

Defines the mapping between data and shape. The value can be a String matching a key in each data point (default is "id"), or an accessor Function that returns a unique value for each data point. Additionally, an Array of these values may be provided if the visualization supports nested hierarchies.

Direction of the ring value labels, in degrees clockwise from 12 o'clock.

Linear scale

Section titled “Linear scale”

radialScale: "linear" makes each wedge’s length, rather than its area, proportional to its value. innerRadius opens an empty center, padPixel an even gap between wedges, and an array of levels sets the exact value rings.

radialScale

How values map onto radii: "sqrt" (default) makes each wedge's area proportional to its value; "linear" makes its radius proportional.

The radius of the empty center, in pixels, or a function of the outer radius.

Crowded categories

Section titled “Crowded categories”

When the category labels would overlap reading horizontally, each one turns to run along its wedge’s spoke instead, and the circle shrinks just enough for them to fit.

Room (px) reserved around the circle for the category labels, or "auto" to size the circle to the measured labels.

Small multiples

Section titled “Small multiples”

facet draws one rose per region, side by side and sharing one legend. By default each panel’s rings fit its own values.

Splits the chart into small multiples: a grid of equally sized panels, one per distinct value of this data key or accessor, each drawing the chart for that value's rows. The panels share one legend, color scale, title, and timeline, color each series the same way, and hover, tooltips, and legend clicks apply across all of them. Pass false to draw a single chart. See facetConfig for the grid's layout and shared scales.

Shared value domain

Section titled “Shared value domain”

With facetConfig: {scales: "shared"}, every panel uses one value domain across all panels, so a smaller region draws a smaller rose.

Splits the chart into small multiples: a grid of equally sized panels, one per distinct value of this data key or accessor, each drawing the chart for that value's rows. The panels share one legend, color scale, title, and timeline, color each series the same way, and hover, tooltips, and legend clicks apply across all of them. Pass false to draw a single chart. See facetConfig for the grid's layout and shared scales.

Configuration

import {PolarArea} from "@d3plus/core";

Extends Viz.

activefalse | function

The active callback function for highlighting shapes.

axisConfigobjectDefault polarAxisConfig

Styles the chrome like a Plot axis: gridConfig the inner value rings, barConfig the outer ring, and shapeConfig.labelConfig the category labels.

classNamestring | array.<string> | undefined

CSS classes added to the outermost element this chart or component draws into, next to its fixed d3plus classes, so page CSS can target it: a chart's root <svg class="d3plus-viz"> (its <canvas> with the Canvas renderer) and a standalone component's <svg>. Takes a space-separated string or an array. A new value replaces the classes the previous one added; unset adds none. Tooltips take their own tooltipConfig.className.

colorDefaultscolordefaultsconfig

Overrides the default colors used when assigning fills from data and choosing legible text colors: dark and light (the text colors picked for contrast against a background), missing (null/undefined values), on/off (true/false values), sequential (the anchor hue for magnitude ramps), and scale (the categorical palette, given as a d3 ordinal scale or an array of colors). Keys are merged into the current defaults, and a Viz passes its overrides down to the shapes and components it draws.

configd3plusconfig

Methods that correspond to the key/value pairs and returns this class.

datastring | array.&lt;datapoint&gt; | object

The primary data array used to draw the visualization. The value passed should be an Array of objects or a String representing a filepath or URL to be loaded. The following filetypes are supported: csv, tsv, txt, and json.

If your data URL needs specific headers to be set, an Object with a "url" and "headers" (or any other fetch request option) may also be passed. An Object with any other key is a data row, not a request.

Additionally, a custom formatting function can be passed as a second argument to this method. This custom function will be passed the data that has been loaded, as long as there are no errors. This function should return the final array of obejcts to be used as the primary data array. For example, some JSON APIs return the headers split from the data values to save bandwidth. These would need be joined using a custom formatter.

If you would like to specify certain configuration options based on the yet-to-be-loaded data, you can also return a full config object from the data formatter (including the new data array as a key in the object).

To re-fetch a URL on an interval and redraw when its data changes, set dataPollingInterval; each poll runs the same formatter.

Defaults to an empty array ([]).

discrete"x" | "y" | "radius" | "angle"Default "metric"

Sets orientation of main category axis.

domain[number, number]

The [min, max] the radius spans. Either end may be left undefined to come from the data, rounded out to nice numbers and including zero.

facetstring | false | function

Splits the chart into small multiples: a grid of equally sized panels, one per distinct value of this data key or accessor, each drawing the chart for that value's rows. The panels share one legend, color scale, title, and timeline, color each series the same way, and hover, tooltips, and legend clicks apply across all of them. Pass false to draw a single chart. See facetConfig for the grid's layout and shared scales.

facetConfigfacetconfig

Configuration for small multiples (see facet), merged into the current config: - columns / rows: the grid's shape. Chosen by default to make the panels as large as the chart's shape allows. - padding: the space between panels, in pixels (default 20). - sort: panel order — "ascending" (default), "descending", "data" (first appearance), a comparator over facet values, or an Array of values. - scales: "shared" (default) gives every panel of a chart with axes the same x/y domains; "independent" fits each panel to its own rows. Funnel defaults to "independent" (each panel sized to its own widest stage); "shared" sizes every panel against the widest stage across all panels. PolarArea and RadialBar default to "independent" (each panel's rings and ticks fit its own values); "shared" gives every panel the same value domain. - axes: with shared scales, "outer" (default) labels the axes only along the grid's left and bottom edges; "all" labels every panel. An object sets each axis on its own, as in {x: "all", y: "outer"}: every panel labels its x axis, only the left column labels its y axis, and the panels' plot areas line up. BumpChart defaults to "all", and Marimekko labels its categories on every panel and its 0–100% share axis only along the outer edge, even with independent scales. - title: a (value, data) => string function for each panel's title, or false to hide panel titles. - titleConfig: TextBox config for the panel titles (fontSize, fontWeight, fontColor, textAnchor, padding, …).

fontFamilystring | array.&lt;string&gt;

The font family used throughout the visualization.

groupBystring | function | array.&lt;string | function&gt;

Defines the mapping between data and shape. The value can be a String matching a key in each data point (default is "id"), or an accessor Function that returns a unique value for each data point. Additionally, an Array of these values may be provided if the visualization supports nested hierarchies.

highlightfalse | function

Persistently emphasizes the data points matching the given predicate: the matching marks keep their color while every other mark is de-emphasized to a neutral gray (the "emphasis" form — highlight one series, gray the rest). Unlike hover/active (transient, opacity-based), highlight is a standing state that survives pointer movement. Pass false to clear it.

hoverfalse | function

The hover callback function for highlighting shapes on mouseover.

innerRadiusnumber | functionDefault 0

The radius of the empty center, in pixels, or a function of the outer radius.

legendboolean | functionDefault rowLegend

Whether to display the legend. By default, the legend shows when it has more than one entry and each entry stands for a single group (or two groups at most), or when the entries are colored by a category that isn't a groupBy level (see color), in which case each entry is labelled by its category. Pass false to hide it, true to always show it, or a (config, data) => boolean function to decide.

legendTooltiptooltipconfigDefault {tbody: []}

Configuration object for the legend tooltip.

levelFormatfunction

Formats the ring value labels. Defaults to the abbreviated number format.

levelLabelAnglenumberDefault 0

Direction of the ring value labels, in degrees clockwise from 12 o'clock.

levelLabelConfigobjectDefault {}

Styles the ring value labels: fontColor, fontFamily, fontOpacity, fontSize, fontWeight.

levelLabelsbooleanDefault true

Whether each value ring is labeled with its value.

levelsnumber | number[]Default 4

The value rings: an approximate count (the domain rounds out to nice values and the rings sit on its ticks), or an array of exact values.

localestring | object

The locale used for all text and number formatting. Supports the locales defined in d3plus-format. The locale can be a complex Object, a locale code (like "en-US"), or a 2-digit language code (like "en"). If a 2-digit code is provided, the "findLocale" function is used to identify the most approximate locale.

metricstring | function

The category each wedge belongs to. Rows sharing a metric share one slice of the circle, their groupBy groups stacked outward from the center in data order. Unset, every row is its own category.

onstring

Event listener for the specified event typenames. Mirrors the core d3-selection behavior.

outerPaddingnumber | "auto"Default "auto"

Room (px) reserved around the circle for the category labels, or "auto" to size the circle to the measured labels.

padAngleunknownDefault 0

Angular gap between neighboring wedges, in radians; overrides padPixel.

padPixelunknownDefault 0

Gap between neighboring wedges, in pixels.

parentunknown

Parent config used by the wrapper.

radialScale"sqrt" | "linear"Default "sqrt"

How values map onto radii: "sqrt" (default) makes each wedge's area proportional to its value; "linear" makes its radius proportional.

renderfunction

Draws the visualization given the specified configuration.

rendererboolean | "svg" | "canvas"

Selects which @d3plus/render backend paints the visible output. "svg" = SvgRenderer (default), "canvas" = CanvasRenderer. Boolean arguments both normalize to "svg".

selectstring | htmlelement

The SVG container element as a d3 selector or DOM element. Defaults to undefined.

shapeConfigd3plusconfig

Configuration object with key/value pairs applied as method calls on each shape.

startAngleunknownDefault 0

Where the first category starts, in degrees clockwise from 12 o'clock.

thresholdnumber | function

The threshold value for bucketing small data points together, as a share of the total. On a stacked Plot, the series whose summed value across every position is under that share of the whole chart's total merge into one series, stacked on top. A bucket needs at least two items, and its tooltips list them. Off (0) by default on Plot charts.

thresholdKeystring | function

Accessor for the value used in the threshold algorithm. A stacked Plot defaults to its stacked value.

timestring | false | function

Accessor function or string key for the time dimension of each data point.

timelineDefaultstring | date | array.&lt;string | date&gt;

The starting time or range for the timeline. Can be a single Date/String, or an Array of 2 values representing the min and max.

tooltipConfigtooltipconfigDefault function

Configuration for the tooltip component.

totalstring | boolean | function

Accessor function or string key for the total value displayed in the visualization.

translatefunction

Defines how informational text strings should be displayed. By default, this function will try to find the string in question (which is the first argument provided to this function) inside of an internally managed translation Object. If you'd like to override to use custom text, simply pass this method your own custom formatting function.

valuestring | functionDefault "value"

Accessor for each row's value.