@types/d3-shape

method centroid

centroid: (d: Datum, ...args: any[]) => [number, number];

• Computes the midpoint [x, y] of the center line of the arc that would be generated by the given arguments.

  To be consistent with the generated arc, the accessors must be deterministic, i.e., return the same value given the same arguments. The midpoint is defined as (startAngle + endAngle) / 2 and (innerRadius + outerRadius) / 2.

  Note that this is not the geometric center of the arc, which may be outside the arc; this method is merely a convenience for positioning labels.

  The method is invoked in the same "this" context as the generator was invoked in and receives the same arguments that are passed into the arc generator.

  Parameter d

  The datum for which the arc is to be generated.

method context

context: {
    (): CanvasRenderingContext2D | null;
    (context: CanvasRenderingContext2D): this;
};

• Returns the current rendering context, which defaults to null.

• Sets the context and returns this arc generator. If context is not specified, returns the current context, which defaults to null.

method cornerRadius

cornerRadius: {
    (): (this: This, d: Datum, ...args: any[]) => number;
    (radius: number): this;
    (radius: (this: This, d: Datum, ...args: any[]) => number): this;
};

• Returns the current corner radius accessor, which defaults to a function returning a constant value of zero.

• Sets the corner radius to the specified number and returns this arc generator.

  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.

  The corner radius may not be larger than (outerRadius - innerRadius) / 2. In addition, for arcs whose angular span is less than π, the corner radius may be reduced as two adjacent rounded corners intersect. This is occurs more often with the inner corners.

  Parameter radius

  Constant radius.

• Sets the corner radius to the specified function and returns this arc generator.

  The corner radius may not be larger than (outerRadius - innerRadius) / 2. In addition, for arcs whose angular span is less than π, the corner radius may be reduced as two adjacent rounded corners intersect. This is occurs more often with the inner corners.

  Parameter radius

  An accessor function returning a number to be used as a radius. The accessor function is invoked in the same "this" context as the generator was invoked in and receives the same arguments that were passed into the arc generator.

method endAngle

endAngle: {
    (): (this: This, d: Datum, ...args: any[]) => number;
    (angle: number): this;
    (angle: (this: This, d: Datum, ...args: any[]) => number): this;
};

• Returns the current end angle accessor, which defaults to a function returning the endAngle property of the first argument passed into it.

• Sets the end angle to the specified number and returns this arc generator.

  The angle is specified in radians, with 0 at -y (12 o’clock) and positive angles proceeding clockwise. If |endAngle - startAngle| ≥ τ, a complete circle or annulus is generated rather than a sector.

  Parameter angle

  Constant angle in radians.

• Sets the end angle to the specified function and returns this arc generator.

  The angle is specified in radians, with 0 at -y (12 o’clock) and positive angles proceeding clockwise. If |endAngle - startAngle| ≥ τ, a complete circle or annulus is generated rather than a sector.

  Parameter angle

  An accessor function returning a number in radians to be used as an angle. The accessor function is invoked in the same "this" context as the generator was invoked in and receives the same arguments that were passed into the arc generator.

method innerRadius

innerRadius: {
    (): (this: This, d: Datum, ...args: any[]) => number;
    (radius: number): this;
    (radius: (this: This, d: Datum, ...args: any[]) => number): this;
};

• Returns the current inner radius accessor, which defaults to a function returning the innerRadius property of the first argument passed into it.

• Sets the inner radius to the specified number and returns this arc generator.

  Specifying the inner radius as a function is useful for constructing a stacked polar bar chart, often in conjunction with a sqrt scale. More commonly, a constant inner radius is used for a donut or pie chart. If the outer radius is smaller than the inner radius, the inner and outer radii are swapped. A negative value is treated as zero.

  Parameter radius

  Constant radius.

• Sets the inner radius to the specified function and returns this arc generator.

  Specifying the inner radius as a function is useful for constructing a stacked polar bar chart, often in conjunction with a sqrt scale. More commonly, a constant inner radius is used for a donut or pie chart. If the outer radius is smaller than the inner radius, the inner and outer radii are swapped. A negative value is treated as zero.

  Parameter radius

  An accessor function returning a number to be used as a radius. The accessor function is invoked in the same "this" context as the generator was invoked in and receives the same arguments that were passed into the arc generator.

method outerRadius

outerRadius: {
    (): (this: This, d: Datum, ...args: any[]) => number;
    (radius: number): this;
    (radius: (this: This, d: Datum, ...args: any[]) => number): this;
};

• Returns the current outer radius accessor, which defaults to a function returning the outerRadius property of the first argument passed into it.

• Sets the outer radius to the specified number and returns this arc generator.

  Specifying the outer radius as a function is useful for constructing a coxcomb or polar bar chart, often in conjunction with a sqrt scale. More commonly, a constant outer radius is used for a pie or donut chart. If the outer radius is smaller than the inner radius, the inner and outer radii are swapped. A negative value is treated as zero.

  Parameter radius

  Constant radius.

• Sets the outer radius to the specified function and returns this arc generator.

  Specifying the outer radius as a function is useful for constructing a coxcomb or polar bar chart, often in conjunction with a sqrt scale. More commonly, a constant outer radius is used for a pie or donut chart. If the outer radius is smaller than the inner radius, the inner and outer radii are swapped. A negative value is treated as zero.

  Parameter radius

  An accessor function returning a number to be used as a radius. The accessor function is invoked in the same "this" context as the generator was invoked in and receives the same arguments that were passed into the arc generator.

method padAngle

padAngle: {
    (): (this: This, d: Datum, ...args: any[]) => number | undefined;
    (angle: number): this;
    (angle: (this: This, d: Datum, ...args: any[]) => number): this;
};

• Returns the current pad angle accessor, which defaults to a function returning the padAngle property of the first argument passed into it, or false if no data are passed in or the property is not defined.

• Sets the pad angle to the specified number and returns this arc generator.

  The pad angle is converted to a fixed linear distance separating adjacent arcs, defined as padRadius * padAngle. This distance is subtracted equally from the start and end of the arc. If the arc forms a complete circle or annulus, as when |endAngle - startAngle| ≥ τ, the pad angle is ignored. If the inner radius or angular span is small relative to the pad angle, it may not be possible to maintain parallel edges between adjacent arcs. In this case, the inner edge of the arc may collapse to a point, similar to a circular sector. For this reason, padding is typically only applied to annular sectors (i.e., when innerRadius is positive).

  The recommended minimum inner radius when using padding is outerRadius * padAngle / sin(θ), where θ is the angular span of the smallest arc before padding. For example, if the outer radius is 200 pixels and the pad angle is 0.02 radians, a reasonable θ is 0.04 radians, and a reasonable inner radius is 100 pixels.

  Often, the pad angle is not set directly on the arc generator, but is instead computed by the pie generator so as to ensure that the area of padded arcs is proportional to their value; see pie.padAngle. See the pie padding animation for illustration. If you apply a constant pad angle to the arc generator directly, it tends to subtract disproportionately from smaller arcs, introducing distortion.

  Parameter angle

  Constant angle in radians.

• Sets the pad angle to the specified function and returns this arc generator.

  The pad angle is converted to a fixed linear distance separating adjacent arcs, defined as padRadius * padAngle. This distance is subtracted equally from the start and end of the arc. If the arc forms a complete circle or annulus, as when |endAngle - startAngle| ≥ τ, the pad angle is ignored. If the inner radius or angular span is small relative to the pad angle, it may not be possible to maintain parallel edges between adjacent arcs. In this case, the inner edge of the arc may collapse to a point, similar to a circular sector. For this reason, padding is typically only applied to annular sectors (i.e., when innerRadius is positive).

  The recommended minimum inner radius when using padding is outerRadius * padAngle / sin(θ), where θ is the angular span of the smallest arc before padding. For example, if the outer radius is 200 pixels and the pad angle is 0.02 radians, a reasonable θ is 0.04 radians, and a reasonable inner radius is 100 pixels.

  Often, the pad angle is not set directly on the arc generator, but is instead computed by the pie generator so as to ensure that the area of padded arcs is proportional to their value; see pie.padAngle. See the pie padding animation for illustration. If you apply a constant pad angle to the arc generator directly, it tends to subtract disproportionately from smaller arcs, introducing distortion.

  Parameter angle

  An accessor function returning a number in radians to be used as an angle. The accessor function is invoked in the same "this" context as the generator was invoked in and receives the same arguments that were passed into the arc generator.

method padRadius

padRadius: {
    (): (this: This, d: Datum, ...args: any[]) => number;
    (radius: number | ((this: This, d: Datum, ...args: any[]) => number)): this;
};

• Returns the current pad radius accessor, which defaults to null, indicating that the pad radius should be automatically computed as sqrt(innerRadius * innerRadius + outerRadius * outerRadius).

• Sets the pad radius to the specified function or number and returns this arc generator. The pad radius determines the fixed linear distance separating adjacent arcs, defined as padRadius * padAngle.

method startAngle

startAngle: {
    (): (this: This, d: Datum, ...args: any[]) => number;
    (angle: number): this;
    (angle: (this: This, d: Datum, ...args: any[]) => number): this;
};

• Returns the current start angle accessor, which defaults to a function returning the startAngle property of the first argument passed into it.

• Sets the start angle to the specified number and returns this arc generator.

  The angle is specified in radians, with 0 at -y (12 o’clock) and positive angles proceeding clockwise. If |endAngle - startAngle| ≥ τ, a complete circle or annulus is generated rather than a sector.

  Parameter angle

  Constant angle in radians.

• Sets the start angle to the specified function and returns this arc generator.

  The angle is specified in radians, with 0 at -y (12 o’clock) and positive angles proceeding clockwise. If |endAngle - startAngle| ≥ τ, a complete circle or annulus is generated rather than a sector.

  Parameter angle

  An accessor function returning a number in radians to be used as an angle. The accessor function is invoked in the same "this" context as the generator was invoked in and receives the same arguments that were passed into the arc generator.

call signature

(this: This, d: Datum, ...args: any[]): string | null;

• Generates an arc for the given arguments.

  IMPORTANT: If the rendering context of the arc generator is null, then the arc is returned as a path data string.

  The "this" context within which this function is invoked, will be the context within which the accessor methods of the generator are invoked. All arguments passed into this function, will be passed to the accessor functions of the generator.

  Parameter d

  The datum for which the arc is to be generated.

call signature

(this: This, d: Datum, ...args: any[]): void;

• Generates an arc for the given arguments.

  IMPORTANT: If the arc generator has been configured with a rendering context, then the arc is rendered to this context as a sequence of path method calls and this function returns void.

  The "this" context within which this function is invoked, will be the context within which the accessor methods of the generator are invoked. All arguments passed into this function, will be passed to the accessor functions of the generator.

  Parameter d

  The datum for which the arc is to be generated.

method context

context: {
    (): CanvasRenderingContext2D | null;
    (context: CanvasRenderingContext2D): this;
};

• Returns the current rendering context, which defaults to null.

• Sets the context and returns this area generator.

method curve

curve: {
    (): CurveFactory;
    <C extends CurveFactory>(): C;
    (curve: CurveFactory): this;
};

• Returns the current curve factory, which defaults to curveLinear.

• Returns the current curve factory, which defaults to curveLinear.

  The generic allows to cast the curve factory to a specific type, if known.

• Sets the curve factory and returns this area generator.

  Parameter curve

  A valid curve factory.

method defined

defined: {
    (): (d: Datum, index: number, data: Datum[]) => boolean;
    (defined: boolean): this;
    (defined: (d: Datum, index: number, data: Datum[]) => boolean): this;
};

• Returns the current defined accessor, which defaults to a function returning a constant boolean value of true.

• Sets the defined accessor to the specified boolean and returns this area generator.

  The default accessor for defined returns a constant boolean value of true, thus assumes that the input data is always defined. When an area is generated, the defined accessor will be invoked for each element in the input data array, being passed the element d, the index i, and the array data as three arguments. If the given element is defined (i.e., if the defined accessor returns a truthy value for this element), the x0, x1, y0 and y1 accessors will subsequently be evaluated and the point will be added to the current area segment. Otherwise, the element will be skipped, the current area segment will be ended, and a new area segment will be generated for the next defined point. As a result, the generated area may have several discrete segments.

  Note that if an area segment consists of only a single point, it may appear invisible unless rendered with rounded or square line caps. In addition, some curves such as curveCardinalOpen only render a visible segment if it contains multiple points.

  Parameter defined

  A boolean constant.

• Sets the defined accessor to the specified function and returns this area generator.

  The default accessor for defined returns a constant boolean value of true, thus assumes that the input data is always defined.

  The default accessor for defined returns a constant boolean value of true, thus assumes that the input data is always defined. When an area is generated, the defined accessor will be invoked for each element in the input data array, being passed the element d, the index i, and the array data as three arguments. If the given element is defined (i.e., if the defined accessor returns a truthy value for this element), the x0, x1, y0 and y1 accessors will subsequently be evaluated and the point will be added to the current area segment. Otherwise, the element will be skipped, the current area segment will be ended, and a new area segment will be generated for the next defined point. As a result, the generated area may have several discrete segments.

  Note that if an area segment consists of only a single point, it may appear invisible unless rendered with rounded or square line caps. In addition, some curves such as curveCardinalOpen only render a visible segment if it contains multiple points.

  Parameter defined

  An accessor function which returns a boolean value. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method lineX0

lineX0: () => Line<Datum>;

• Returns a new line generator that has this area generator’s current defined accessor, curve and context. The line’s x-accessor is this area’s x0-accessor, and the line’s y-accessor is this area’s y0-accessor.

method lineX1

lineX1: () => Line<Datum>;

• Returns a new line generator that has this area generator’s current defined accessor, curve and context. The line’s x-accessor is this area’s x1-accessor, and the line’s y-accessor is this area’s y0-accessor.

method lineY0

lineY0: () => Line<Datum>;

• Returns a new line generator that has this area generator’s current defined accessor, curve and context. The line’s x-accessor is this area’s x0-accessor, and the line’s y-accessor is this area’s y0-accessor.

method lineY1

lineY1: () => Line<Datum>;

• Returns a new line generator that has this area generator’s current defined accessor, curve and context. The line’s x-accessor is this area’s x0-accessor, and the line’s y-accessor is this area’s y1-accessor.

method x

x: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (x: number): this;
    (x: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current x0 accessor. The default x0 accessor is a function returning the first element of a two-element array of numbers.

• Sets x0 to a constant number x and x1 to null and returns this area generator.

  Setting x1 to null indicates that the previously-computed x0 value should be reused for the x1 value.

  Parameter x

  A constant value to be used for x0.

• Sets x0 to the specified function x and x1 to null and returns this area generator.

  The default x0 accessor assumes that the input data are two-element arrays of numbers and returns the first element. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter x

  An accessor function returning a value to be used for x0. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method x0

x0: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (x: number): this;
    (x: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current x0 accessor. The default x0 accessor is a function returning the first element of a two-element array of numbers.

• Sets x0 to a constant number and returns this area generator.

  Parameter x

  A constant value.

• Sets x0 to the specified function and returns this area generator.

  The default x0 accessor assumes that the input data are two-element arrays of numbers and returns the first element. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter x

  An accessor function returning a value to be used for x0. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method x1

x1: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (x: number): this;
    (x: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current x1 accessor, which defaults to null, indicating that the previously-computed x0 value should be reused for the x1 value.

• Sets the x1 accessor to the specified number and returns this area generator.

• Sets x1 to the specified function and returns this area generator.

  The default x1 accessor is null, indicating that the previously-computed x0 value should be reused for the x1 value. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter x

  An accessor function returning a value to be used for x1. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method y

y: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (y: number): this;
    (y: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current y0 accessor. The default y0 accessor is a function returning a constant value of zero.

• Sets y0 to a constant number y and y1 to null and returns this area generator.

  Setting y1 to null indicates that the previously-computed y0 value should be reused for the y1 value.

  Parameter y

  A constant value to be used for y0.

• Sets y0 to the accessor function y and y1 to null and returns this area generator.

  The default y0 accessor returns a constant value of zero. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter y

  An accessor function returning a value to be used for y0. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method y0

y0: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (y: number): this;
    (y: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current y0 accessor. The default y0 accessor is a function a constant value of zero.

• Sets y0 to a constant number and returns this area generator.

  Parameter y

  A constant value.

• Sets y0 to the specified function and returns this area generator.

  The default y0 accessor is a function which returns a constant value of zero. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter y

  An accessor function returning a value to be used for y0. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method y1

y1: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (y: number): this;
    (y: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current y1 accessor or null. The default y1 accessor is a function returning the second element of a two-element array of numbers.

  If the y1 accessor is null, the previously-computed y0 value is reused for the y1 value.

• sets the y1 accessor to the specified number and returns this area generator.

• Sets y1 to the specified function and returns this area generator.

  The default y1 accessor assumes that the input data are two-element arrays of numbers and returns the second element. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter y

  An accessor function returning a value to be used for y1. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

call signature

(data: Iterable<Datum> | Datum[]): string | null;

• Generates an area for the given array of data. Depending on this area generator’s associated curve, the given input data may need to be sorted by x-value before being passed to the area generator.

  IMPORTANT: If the rendering context of the area generator is null, then the area is returned as a path data string.

  Parameter data

  Array of data elements.

call signature

(data: Iterable<Datum> | Datum[]): void;

• Generates an area for the given array of data. Depending on this area generator’s associated curve, the given input data may need to be sorted by x-value before being passed to the area generator.

  IMPORTANT: If the area generator has been configured with a rendering context, then the area is rendered to this context as a sequence of path method calls and this function returns void.

  Parameter data

  Array of data elements.

method angle

angle: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (angle: number): this;
    (angle: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current startAngle accessor. The default startAngle accessor is a function returning the first element of a two-element array of numbers.

• Sets startAngle to a constant number angle and endAngle to null and returns this radial area generator.

  Setting endAngle to null indicates that the previously-computed startAngle value should be reused for the endAngle value.

  Parameter angle

  A constant value in radians with 0 at -y (12 o’clock).

• Sets startAngle to the specified function angle and endAngle to null and returns this radial area generator.

  The default startAngle accessor assumes that the input data are two-element arrays of numbers and returns the first element. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter angle

  An accessor function returning a value to be used for startAngle in radians with 0 at -y (12 o’clock). The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method context

context: {
    (): CanvasRenderingContext2D | null;
    (context: CanvasRenderingContext2D): this;
};

• Returns the current rendering context, which defaults to null.

• Equivalent to line.context.

method curve

curve: {
    (): CurveFactory;
    <C extends CurveFactory>(): C;
    (curve: CurveFactory): this;
};

• Returns the current curve factory, which defaults to curveLinear.

• Returns the current curve factory, which defaults to curveLinear.

  The generic allows to cast the curve factory to a specific type, if known.

• Sets the curve factory and returns this radial area generator.

  Note that curveMonotoneX or curveMonotoneY are not recommended for radial areas because they assume that the data is monotonic in x or y, which is typically untrue of radial areas.

  Parameter curve

  A valid curve factory.

method defined

defined: {
    (): (d: Datum, index: number, data: Datum[]) => boolean;
    (defined: boolean): this;
    (defined: (d: Datum, index: number, data: Datum[]) => boolean): this;
};

• Returns the current defined accessor, which defaults to a function returning a constant boolean value of true.

• Sets the defined accessor to the specified boolean and returns this radial area generator.

  The default accessor for defined returns a constant boolean value of true, thus assumes that the input data is always defined.

  When a radial area is generated, the defined accessor will be invoked for each element in the input data array, being passed the element d, the index i, and the array data as three arguments. If the given element is defined (i.e., if the defined accessor returns a truthy value for this element), the startAngle, endAngle, innerRadius and outerRadius accessors will subsequently be evaluated and the point will be added to the current area segment.

  Otherwise, the element will be skipped, the current area segment will be ended, and a new area segment will be generated for the next defined point. As a result, the generated area may have several discrete segments.

  Note that if an area segment consists of only a single point, it may appear invisible unless rendered with rounded or square line caps. In addition, some curves such as curveCardinalOpen only render a visible segment if it contains multiple points.

  Parameter defined

  A boolean constant.

• Sets the defined accessor to the specified function and returns this radial area generator.

  The default accessor for defined returns a constant boolean value of true, thus assumes that the input data is always defined.

  When a radial area is generated, the defined accessor will be invoked for each element in the input data array, being passed the element d, the index i, and the array data as three arguments. If the given element is defined (i.e., if the defined accessor returns a truthy value for this element), the startAngle, endAngle, innerRadius and outerRadius accessors will subsequently be evaluated and the point will be added to the current area segment.

  Otherwise, the element will be skipped, the current area segment will be ended, and a new area segment will be generated for the next defined point. As a result, the generated area may have several discrete segments.

  Note that if an area segment consists of only a single point, it may appear invisible unless rendered with rounded or square line caps. In addition, some curves such as curveCardinalOpen only render a visible segment if it contains multiple points.

  Parameter defined

  An accessor function which returns a boolean value. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method endAngle

endAngle: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (angle: number): this;
    (angle: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current endAngle accessor, which defaults to null, indicating that the previously-computed startAngle value should be reused for the endAngle value.

• Equivalent to area.x1, except the accessor returns the angle in radians, with 0 at -y (12 o’clock). Note: typically angle is used instead of setting separate start and end angles.

• Sets endAngle to the specified function and returns this radial area generator.

  The default endAngle accessor is null, indicating that the previously-computed startAngle value should be reused for the endAngle value. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter angle

  An accessor function returning a value to be used for endAngle in radians with 0 at -y (12 o’clock). The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method innerRadius

innerRadius: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (radius: number): this;
    (radius: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current innerRadius accessor. The default innerRadius accessor is a function a constant value of zero.

• Sets innerRadius to a constant number and returns this radial area generator.

  Parameter radius

  A constant value.

• Sets innerRadius to the specified function and returns this radial area generator.

  The default innerRadius accessor is a function which returns a constant value of zero. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter radius

  An accessor function returning a value to be used for innerRadius. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method lineEndAngle

lineEndAngle: () => LineRadial<Datum>;

• Returns a new radial line generator that has this radial area generator’s current defined accessor, curve and context. The line’s angle accessor is this area’s end angle accessor, and the line’s radius accessor is this area’s inner radius accessor.

method lineInnerRadius

lineInnerRadius: () => LineRadial<Datum>;

• Returns a new radial line generator that has this radial area generator’s current defined accessor, curve and context. The line’s angle accessor is this area’s start angle accessor, and the line’s radius accessor is this area’s inner radius accessor.

method lineOuterRadius

lineOuterRadius: () => LineRadial<Datum>;

• Returns a new radial line generator that has this radial area generator’s current defined accessor, curve and context. The line’s angle accessor is this area’s start angle accessor, and the line’s radius accessor is this area’s outer radius accessor.

method lineStartAngle

lineStartAngle: () => LineRadial<Datum>;

• Returns a new radial line generator that has this radial area generator’s current defined accessor, curve and context. The line’s angle accessor is this area’s start angle accessor, and the line’s radius accessor is this area’s inner radius accessor.

method outerRadius

outerRadius: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (radius: number): this;
    (radius: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current outerRadius accessor or null. The default outerRadius accessor is a function returning the second element of a two-element array of numbers.

  If the outerRadius accessor is null, the previously-computed innerRadius value is reused for the outerRadius value.

• Equivalent to area.y1, except the accessor returns the radius: the distance from the origin ⟨0,0⟩.

• Sets outerRadius to the specified function and returns this radial area generator.

  The default outerRadius accessor assumes that the input data are two-element arrays of numbers and returns the second element. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter radius

  An accessor function returning a value to be used for outerRadius. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method radius

radius: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (radius: number): this;
    (radius: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current innerRadius accessor. The default innerRadius accessor is a function returning a constant value of zero.

• Sets innerRadius to a constant number radius and outerRadius to null and returns this radial area generator.

  Setting outerRadius to null indicates that the previously-computed innerRadius value should be reused for the outerRadius value.

  Parameter radius

  A constant value to be used for innerRadius.

• Sets innerRadius to the accessor function radius and outerRadius to null and returns this radial area generator.

  The default innerRadius accessor returns a constant value of zero. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter radius

  An accessor function returning a value to be used for innerRadius. The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

method startAngle

startAngle: {
    (): (d: Datum, index: number, data: Datum[]) => number;
    (angle: number): this;
    (angle: (d: Datum, index: number, data: Datum[]) => number): this;
};

• Returns the current startAngle accessor. The default startAngle accessor is a function returning the first element of a two-element array of numbers.

• Sets startAngle to a constant number and returns this radial area generator.

  Parameter angle

  A constant value in radians with 0 at -y (12 o’clock).

• Sets startAngle to the specified function and returns this radial area generator.

  The default startAngle accessor assumes that the input data are two-element arrays of numbers and returns the first element. If your data are in a different format, or if you wish to transform the data before rendering, then you should specify a custom accessor.

  Parameter angle

  An accessor function returning a value to be used for startAngle in radians with 0 at -y (12 o’clock). The accessor will be invoked for each defined element in the input data array, being passed the element d, the index i, and the array data as three arguments.

call signature

(data: Iterable<Datum> | Datum[]): string | null;

• Generates a radial area for the given array of data.

  IMPORTANT: If the rendering context of the radial area generator is null, then the radial area is returned as a path data string.

  Parameter data

  Array of data elements.

call signature

(data: Iterable<Datum> | Datum[]): void;

• Generates a radial area for the given array of data.

  IMPORTANT: If the radial area generator has been configured with a rendering context, then the radial area is rendered to this context as a sequence of path method calls and this function returns void.

  Parameter data

  Array of data elements.

method arc

arc: (
    x: number,
    y: number,
    radius: number,
    startAngle: number,
    endAngle: number,
    anticlockwise?: boolean
) => void;

method arcTo

arcTo: (x1: number, y1: number, x2: number, y2: number, radius: number) => void;

method bezierCurveTo

bezierCurveTo: (
    cp1x: number,
    cp1y: number,
    cp2x: number,
    cp2y: number,
    x: number,
    y: number
) => void;

method closePath

closePath: () => void;

method ellipse

ellipse: (
    x: number,
    y: number,
    radiusX: number,
    radiusY: number,
    rotation: number,
    startAngle: number,
    endAngle: number,
    anticlockwise?: boolean
) => void;

method lineTo

lineTo: (x: number, y: number) => void;

method moveTo

moveTo: (x: number, y: number) => void;

method quadraticCurveTo

quadraticCurveTo: (cpx: number, cpy: number, x: number, y: number) => void;

method rect

rect: (x: number, y: number, w: number, h: number) => void;

method beta

beta: (beta: number) => this;

• Returns a bundle curve factory with the specified beta in the range [0, 1], representing the bundle strength. If beta equals zero, a straight line between the first and last point is produced; if beta equals one, a standard basis spline is produced.

  Parameter beta

  A constant value in the [0, 1] interval.

method tension

tension: (tension: number) => this;

• Returns a cardinal curve factory with the specified tension in the range [0, 1]. The tension determines the length of the tangents: a tension of one yields all zero tangents, equivalent to curveLinear; a tension of zero produces a uniform Catmull–Rom spline.

  Parameter tension

  A constant in the [0, 1] interval.

method alpha

alpha: (alpha: number) => this;

• Returns a cubic Catmull–Rom curve factory with the specified alpha in the range [0, 1]. If alpha is zero, produces a uniform spline, equivalent to curveCardinal with a tension of zero; if alpha is one, produces a chordal spline; if alpha is 0.5, produces a centripetal spline. Centripetal splines are recommended to avoid self-intersections and overshoot.

  Parameter alpha

  A constant in the [0, 1] interval.

method areaEnd

areaEnd: () => void;

• Indicates the end of the current area segment.

method areaStart

areaStart: () => void;

• Indicates the start of a new area segment. Each area segment consists of exactly two line segments: the topline, followed by the baseline, with the baseline points in reverse order.

method lineEnd

lineEnd: () => void;

• Indicates the end of the current line segment.

method lineStart

lineStart: () => void;

• Indicates the start of a new line segment. Zero or more points will follow.

method point

point: (x: number, y: number) => void;

• Indicates a new point in the current line segment with the given x- and y-values.

property endAngle

endAngle: number;

• End angle of arc. The angle is specified in radians, with 0 at -y (12 o’clock) and positive angles proceeding clockwise.

property innerRadius

innerRadius: number;

• Inner radius of arc.

property outerRadius

outerRadius: number;

• Outer radius of arc.

property padAngle

padAngle?: number | undefined;

• Optional. Pad angle of arc in radians.

property startAngle

startAngle: number;

• Start angle of arc. The angle is specified in radians, with 0 at -y (12 o’clock) and positive angles proceeding clockwise.

property source

source: [number, number];

• Source node of the link.

  For a link in a Cartesian coordinate system, the two element array contains the coordinates [x, y].

  For a radial link, the two element array contains the coordinates [angle, radius]. The angle is stated in radians, with 0 at -y (12 o’clock). The radius measures the distance from the origin ⟨0,0⟩.

property target

target: [number, number];

• Target node of the link.

  For a link in a Cartesian coordinate system, the two element array contains the coordinates [x, y].

  For a radial link, the two element array contains the coordinates [angle, radius]. The angle is stated in radians, with 0 at -y (12 o’clock). The radius measures the distance from the origin ⟨0,0⟩.

method context

context: {
    (): CanvasRenderingContext2D | null;
    (context: CanvasRenderingContext2D): this;
};

• Returns the current rendering context, which defaults to null.

• Sets the context and returns this line generator.

method curve

curve: {
    (): CurveFactory | CurveFactoryLineOnly;
    <C extends CurveFactory | CurveFactoryLineOnly>(): C;
    (curve: CurveFactory | CurveFactoryLineOnly): this;
};