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Ribbons ​

A ribbon visually represents the volume of flow between two nodes in a chord diagram. Ribbons come in two varieties: ribbon represents a bidirectional flow, while ribbonArrow represents a unidirectional flow. The latter is suitable for chordDirected.

ribbon() ​

Source · Creates a new ribbon generator with the default settings.

js
const ribbon = d3.ribbon();

ribbon(...arguments) ​

Source · Generates a ribbon for the given arguments. The arguments are arbitrary; they are propagated to the ribbon generator’s accessor functions along with the this object. For example, with the default settings, a chord object is expected:

js
ribbon({
  source: {startAngle: 0.7524114, endAngle: 1.1212972, radius: 240},
  target: {startAngle: 1.8617078, endAngle: 1.9842927, radius: 240}
}) // "M164.0162810494058,-175.21032946354026A240,240,0,0,1,216.1595644740915,-104.28347273835429Q0,0,229.9158815306728,68.8381247563705A240,240,0,0,1,219.77316791012538,96.43523560788266Q0,0,164.0162810494058,-175.21032946354026Z"

If the ribbon generator has a context, then the ribbon is rendered to this context as a sequence of path method calls and this function returns void. Otherwise, a path data string is returned.

ribbon.source(source) ​

Source · If source is specified, sets the source accessor to the specified function and returns this ribbon generator. If source is not specified, returns the current source accessor, which defaults to:

js
function source(d) {
  return d.source;
}

ribbon.target(target) ​

Source · If target is specified, sets the target accessor to the specified function and returns this ribbon generator. If target is not specified, returns the current target accessor, which defaults to:

js
function target(d) {
  return d.target;
}

ribbon.radius(radius) ​

Source · If radius is specified, sets the source and target radius accessor to the specified function and returns this ribbon generator. For example to set a fixed radius of 240 pixels:

js
const ribbon = d3.ribbon().radius(240);

Now the arguments you pass to ribbon do not need to specify a radius property on the source and target.

js
ribbon({
  source: {startAngle: 0.7524114, endAngle: 1.1212972},
  target: {startAngle: 1.8617078, endAngle: 1.9842927}
}) // "M164.0162810494058,-175.21032946354026A240,240,0,0,1,216.1595644740915,-104.28347273835429Q0,0,229.9158815306728,68.8381247563705A240,240,0,0,1,219.77316791012538,96.43523560788266Q0,0,164.0162810494058,-175.21032946354026Z"

If radius is not specified, returns the current source radius accessor, which defaults to:

js
function radius(d) {
  return d.radius;
}

ribbon.sourceRadius(radius) ​

Source · If radius is specified, sets the source radius accessor to the specified function and returns this ribbon generator. If radius is not specified, returns the current source radius accessor, which defaults to:

js
function radius(d) {
  return d.radius;
}

ribbon.targetRadius(radius) ​

Source · If radius is specified, sets the target radius accessor to the specified function and returns this ribbon generator. If radius is not specified, returns the current target radius accessor, which defaults to:

js
function radius(d) {
  return d.radius;
}

By convention, the target radius in asymmetric chord diagrams is typically inset from the source radius, resulting in a gap between the end of the directed link and its associated group arc.

ribbon.startAngle(angle) ​

Source · If angle is specified, sets the start angle accessor to the specified function and returns this ribbon generator. If angle is not specified, returns the current start angle accessor, which defaults to:

js
function startAngle(d) {
  return d.startAngle;
}

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

ribbon.endAngle(angle) ​

Source · If angle is specified, sets the end angle accessor to the specified function and returns this ribbon generator. If angle is not specified, returns the current end angle accessor, which defaults to:

js
function endAngle(d) {
  return d.endAngle;
}

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

ribbon.padAngle(angle) ​

Source · If angle is specified, sets the pad angle accessor to the specified function and returns this ribbon generator. If angle is not specified, returns the current pad angle accessor, which defaults to:

js
function padAngle() {
  return 0;
}

The pad angle specifies the angular gap between adjacent ribbons.

ribbon.context(context) ​

Source · If context is specified, sets the context and returns this ribbon generator. If context is not specified, returns the current context, which defaults to null. If the context is not null, then the generated ribbon is rendered to this context as a sequence of path method calls. Otherwise, a path data string representing the generated ribbon is returned. See also d3-path.

ribbonArrow() ​

Source · Creates a new arrow ribbon generator with the default settings. See also chordDirected.

ribbonArrow.headRadius(radius) ​

Source · If radius is specified, sets the arrowhead radius accessor to the specified function and returns this ribbon generator. If radius is not specified, returns the current arrowhead radius accessor, which defaults to:

js
function headRadius() {
  return 10;
}