Cloudera Docs

Chord

Cloudera Data Visualization enables you to create Chord visuals. These visuals expose the inter-relationships between entities, making them an ideal choice for comparing the similarities within a dataset, or between different groups of data. The nodes/dimensions are on the circumference of a circle, and the relationships between them are the arcs inside the circle. The size of the node is proportional to the measurement. Cloudera Data Visualization uses color to help distinguish the overlapping relationship arcs.

Chord visuals are similar to Correlation Heatmaps because they both compare exactly two dimensions. Chords, however, plot dimensions that cover the same value domain, and are better at pointing out the presence of a relationship between nodes than the relative magnitude of that relationship.

The following steps demonstrate how to create a new chord visual on the SF Cabrides dataset. This dataset is based on data previously imported into Cloudera Data Visualization from a datafile. Each distinct line segment between two dimensions reports the correlation data. Because the values for pick-up and drop-off areas, srcarea and tgtarea , are in the same domain, it makes the dataset ideal for demonstrating chord visuals.

For an overview of shelves that specify this visual, see Shelves for chord visuals.

  1. Start a new visual based on the SF Cabrides dataset.
    For instructions, see Creating a visual.
  2. In the VISUALS menu, find and click Chord.
    The shelves of the visual changed. They are now Dimensions, Measure, Tooltips, X Trellis, Y Trellis and Filters. Both Dimensions and Measure are mandatory.
  3. Populate the shelves from the fields available in the DATA menu:
    1. From Dimensions, select srcarea and trgarea, and drag them to the Dimensions shelf.
    2. From Measures, select rides and place it to the Measure shelf.
  4. Click REFRESH VISUAL.

    The Chord visual appears.

    Figure 1. Chord Visual
  5. Optional: Check the details of the individual dimensions:
    1. Hover the pointer over one of the nodes.
      The visual shows the connections that originate or terminate with this specific value, as well as the tooltip. In the following image, you can see all connections for 'South of Market'.
    2. Hover the pointer over one of the connections.
      The tooltip shows the detail for that connection: starting and ending notes, and the measurement.
    Figure 2. Viewing Details of a Chord Visual
  6. Click EDIT next to the title of the visualization, and change the title to 'San Francisco Cab Rides - Chord'.
  7. At the top left corner of the Dashboard Designer, click SAVE.