Chord diagram

A chord diagram template. Lets you visualise connections between two entities.

Updated 6 years ago to v2.2.0 by Flourish team

How to use this template

This template is useful for showing relationships and the flow to and from values. It gives the option to color the chords as linear gradients or have the chords filled based on the source which is determined by the bigger flow.

Data requirements

There must be three columns. The first specifies the values from, the second specifies the values to, and the third is the count (a numerical number describing how many flows there were).

Tips

  • You can change the color based on your needs. By default it is a gradient but you can also use a fill colour. The fill colour is based on the biggest value.

  • If your text label is overlapping and your label alignment is "Along Arcs" your overlapping text label will not show up. This might be convenient for you, but you can also flip the label 90° that way your label won't overlap and will show up.

  • Chord diagrams can be difficult to understand so make sure to add an appropriate title. You can also add a popup to make it easier for the user to understand.

  • Flourish allows you to export an SVG. Do this if you want to add annotations in your favourite vector editing program.

Credits

Created by the Flourish team. Sample data from Crazy for Friends. Want to see additional features? Let us know at support@flourish.studio.

This section documents API usage specific to this template, so for an introduction we suggest you refer to the generic API documentation instead.

template: @flourish/chord-diagram

version: 2

Template data

There are three different formats in which you can supply data to this template. The most convenient for you to use likely depends on the source of your data, as described below.

1. Array of arrays, and a bindings object

You can supply arrays of arrays to opts.data, which might look like:

{
    data: {
        connections: [
            [ "ConnectionsColumn1Value1", "ConnectionsColumn2Value1",
            [ "ConnectionsColumn1Value2", "ConnectionsColumn2Value2",
            [ "ConnectionsColumn1Value3", "ConnectionsColumn2Value3",
            ...
        ]
    }
}

where each array of arrays represents the rows in a data sheet.

To tell the API how the values from each column should be associated with the keys that the template is expecting, you must also supply an object attached to opts.bindings. (The meanings of the keys in the bindings object are documented below.) The minimal bindings you can supply for this template are as shown in this example:

{
    template: "@flourish/chord-diagram",
    version: "2",
    bindings: {
        connections: {
            from: 0, // index of a column in your data
            to: 1, // index of a column in your data
            value: 2, // index of a column in your data
        }
    },
    data: {
        connections: [
            [ "ConnectionsColumn1Value1", "ConnectionsColumn2Value1",
            [ "ConnectionsColumn1Value2", "ConnectionsColumn2Value2",
            [ "ConnectionsColumn1Value3", "ConnectionsColumn2Value3",
            ...
        ]
    }
}

All possible bindings that you can supply are shown in this example:

{
    template: "@flourish/chord-diagram",
    version: "2",
    bindings: {
        connections: {
            from: 0, // index of a column in your data
            to: 1, // index of a column in your data
            value: 2, // index of a column in your data
        }
    },
    data: {
        connections: [
            [ "ConnectionsColumn1Value1", "ConnectionsColumn2Value1",
            [ "ConnectionsColumn1Value2", "ConnectionsColumn2Value2",
            [ "ConnectionsColumn1Value3", "ConnectionsColumn2Value3",
            ...
        ]
    }
}

2. Array of objects with arbitrary keys, and a bindings object

This format is most likely useful when you have data from an external source, such as CSV data loaded from d3-dsv. You should supply this attached to the opts.data, which might look like:

{
        connections: [
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            ...
        ]
    }

... but with the keys being the column headers from your source data instead. You must also supply an object attached to opts.bindings. The minimal bindings you can supply for this template are as shown in this example:

{
    template: "@flourish/chord-diagram",
    version: "2",
    bindings: {
        connections: {
            from: "ConnectionsHeader1",
            to: "ConnectionsHeader2",
            value: "ConnectionsHeader3",
        }
    },
    data: {
        connections: [
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            ...
        ]
    }
}

All possible bindings that you can supply are shown in this example:

{
    template: "@flourish/chord-diagram",
    version: "2",
    bindings: {
        connections: {
            from: "ConnectionsHeader1",
            to: "ConnectionsHeader2",
            value: "ConnectionsHeader3",
        }
    },
    data: {
        connections: [
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            { "ConnectionsHeader1": ..., "ConnectionsHeader2": ..., ... },
            ...
        ]
    }
}

(As before, the keys containing "Header" would be replaced by column names from your data source.)

3. Array of objects with template-defined keys

There is an alternative format you can use, which is likely to be easier to use if your data is not from a spreadsheet source. With this alternative format you supply your data to the template as an array of objects, attached to opts.data, where the keys must be those used by the template, as documented below. In this case there is no need to supply a bindings object, since the key names are already those expected by the template. The required properties in the data object are as follows (scroll down for a description of what each property is):

{
    template: "@flourish/chord-diagram",
    version: "2",
    data: {
    connections: [
        {
            from: ...,
            to: ...,
            value: ...
        },
        ...
    ]
},
    ...
}

And the full list of all possible properties is as follows:

{
    template: "@flourish/chord-diagram",
    version: "2",
    data: {
    connections: [
        {
            from: ...,
            to: ...,
            value: ...
        },
        ...
    ]
},
    ...
}

Meanings of the template data keys:

  • connections.from: from
  • connections.to: to
  • connections.value: A number specifying the size of the flow

Template settings

Options for opts.state.

header.title string

Title.

header.subtitle string

Subtitle.

header.color color

Color.

header.align string

Alignment.

Allowed values:

  • left (fa-align-left)
  • center (fa-align-center)
  • right (fa-align-right)

header.margin number

Margin.

header.margin_advanced boolean

Advanced margin settings.

header.margin_top number

Top.

header.margin_right number

Right.

header.margin_bottom number

Bottom.

header.margin_left number

Left.

Colour

color.palette colors

Palette.

color.extend boolean

Auto-extend. Automatically generate additional colours when needed to avoid the palette colours being used more than once. Added colours are based on the average lightness and chroma values of the palette. This works best if the palette’s colours do not have very high or low saturation.

color.advanced boolean

Fine tune. Fine tune how additional colours are added to the palette.

color.hue_rotation_angle number

Hue rotation for added colours. Angle, in degrees in HCL colourspace, between one generated colour and the next. The default value, ~360/(Golden ratio), ensures adjacent hues are not too similar.

Max: 360

color.custom_palette text

Custom overrides. Type the name of the entity whose colour you want to set, a colon and then a colour (using a name, hex-code or rgb declaration). Multiple colours can be set using multiple lines. For example:


Party 1: red
Party 2: #4455AA
Party 3: rgb(30,168,26)

gradient_type string

Chord colour mode.

Allowed values:

  • linear_gradient (Gradient)
  • largest_end (Larger end)
  • smallest_end (Smaller end)

background_color color

Background color.

Chords

opacity_chord number

Chord Opacity.

Max: 1

selected_chords text

Highlight chords. To highlight an chords ribbons, write the name of each arc on a line. You can also create a story and highlight/unhighlight by clicking.

use_mouseover_label boolean

Show chord values on hover.

show_selected_label boolean

Keep chord values on click.

use_mouseover_chords boolean

Highlight chord on mouseover.

chord_labels_reponsive boolean

Label text size. Auto changed the label size based on the window size, subject to the specified min and max

Allowed values:

  • true (Auto)
  • false (Fixed)

chord_label_font_size number

Text size.

Max: 40

chord_label_font_size_min number

Min size.

Max: 40

chord_label_font_size_max number

Max size.

Max: 40

show_chord_stroke boolean

Allowed values:

  • true (Enabled)
  • false (Disabled)

chord_stroke_color color

Stroke color.

chord_stroke_opacity number

Stroke opacity.

Max: 1

Arcs

arc_spacing number

Space below arcs. in pixels

pad_angle number

Space between arcs. in radians

Max: 1

use_mouseover_arcs boolean

Highlight chords on hover.

label_alignment string

Alignment.

Allowed values:

  • along_arcs (Along Arcs)
  • 90_rotated (90° rotated)

label_responsive boolean

Label text size. Auto changed the label size based on the window size, subject to the specified min and max

Allowed values:

  • true (Auto)
  • false (Fixed)

label_font_size number

Text size.

Max: 40

label_font_size_min number

Min size.

Max: 40

label_font_size_max number

Max size.

Max: 40

label_color color

Arc label color.

use_label_color_arc boolean

Make the arc label color the same as the arc color.

popup.show_popups boolean

Popups.

Allowed values:

  • true (Enabled)
  • false (Disabled)

popup.is_custom boolean

Popup contents.

Allowed values:

  • false (Auto)
  • true (Custom content)

popup.custom_template text

Popup content. The text to appear in the popup. You can use {{column_name}} to add a value from your data. It must be in a selected column, but you can add columns to “Metadata” if you just want to include them for use in the popup. Advanced users can include HTML to apply layouts, formatting, images, etc.

popup.show_pointer boolean

Pointer.

popup.show_shadow boolean

Shadow.

popup.style_popups boolean

Custom styling.

popup.text_color color

Text colour.

popup.align string

Alignment.

Allowed values:

  • left (fa-align-left)
  • center (fa-align-center)
  • right (fa-align-right)

popup.font_size number

Font size.

Min: 1

popup.fill_color color

Fill colour.

popup.opacity number

Fill opacity.

Max: 1

popup.padding number

Padding.

popup.border_radius number

Radius. Corner radius of popup

Position.

Allowed values:

  • directional (Directional)
  • non_directional (Non directional)

Popup Description. Add a title or a discription to help explain your tooltip

footer.source_name string

Source name.

footer.source_url string

Source url.

footer.multiple_sources boolean

Multiple sources.

footer.source_name_2 string

Source name.

footer.source_url_2 string

Source url.

footer.source_name_3 string

Source name.

footer.source_url_3 string

Source url.

footer.source_label string

Source label.

footer.note string

Note.

footer.size number

Size.

footer.color color

Color.

footer.align string

Alignment.

Allowed values:

  • left (fa-align-left)
  • center (fa-align-center)
  • right (fa-align-right)

footer.margin number

Overall.

footer.margin_top number

Top.

footer.margin_right number

Right.

footer.margin_bottom number

Bottom.

footer.margin_left number

Left.

footer.margin_advanced boolean

Advanced.

Animation

animation_speed number

Animation Duration.

Number format

localization.input_decimal_separator string

Decimal separator in data sheet. Used for interpreting your data. Only change if data is not displaying on the chart as expected.

Allowed values:

  • . (.)
  • , (,)

localization.output_separators string

Number format to display. How the numbers should appear on chart labels

Allowed values:

  • ,. (12,235.67)
  • ., (12.345,67)
  • . (12235.67)
  • , (12345,67)
  • . (12 235.67)
  • , (12 345,67)

label_format.prefix string

Prefix. Text to place in front of number

label_format.suffix string

Suffix. Text to place after number

label_format.n_dec number

Decimal places. Use negative integers to round to positive powers of ten (eg -2 rounds to the nearest 100)

Min: -10

Max: 10

label_format.strip_zeros boolean

Remove trailing zeros.

label_format.strip_separator boolean

Hide thousands separator below 10,000. Turn off if you want four-digit numbers to include a separator, e.g. “1,234” rather than “1234”.

label_format.transform_labels boolean

Multiply/divide values.

label_format.transform string

Allowed values:

  • multiply (Multiply by)
  • divide (Divide by)
  • exponentiate (×10 to the power of)

label_format.multiply_divide_constant number

label_format.exponentiate_constant number

Scaling and sizing

chart_scale number

Chart scale.

Max: 1

allow_resize boolean

Allow embeds to resize. Checking this option allows the visualisation to resize so the chord diagram is always a square without white space to the sides or top/bottom.