Dendrogram Visuals

Dendrograms are good at expressing hierarchical relationships in data. As the name derivation suggests (Greek dendro for 'tree' and gramma for 'drawing'), dendrograms are tree diagrams.

We are working with dataset NYC Taxi Data for year 2013.

You can download a subset of this data for trips made within Staten Island boro, upload it, and create the dataset NYC Taxi Data.

  1. Start a new visual based on dataset NYC Taxi Data ; see Creating Visuals.
  2. In the visuals menu, find and click Dendrogram (row 4, column 3).

    selecting dendrogram chart type
  3. Note that the shelves of the visual changed. They are now X, Y, Dimensions, Measures, Tooltips, and Filters.

    The mandatory shelves are:

    • Dimensions: specify two dimensions, because there are at least two nodes on each branch
    • Measures; specify one measurement plotted on the branch between nodes
    shelves of dendrogram visual type
  4. Populate the shelves from the available fields (Dimensions, Measures, and so on) in the Data menu.

    • Under Dimensions, select Pickup Neighborhood and Dropoff Neighborhood, and add them to the Dimensions shelf.
    • Under Measures, select Record Count and add it to the Measures shelf.
  5. To examine only the rides within Staten Island, add Pickup Boro and Dropoff Boro to the Filters shelf, and set them to a single value Staten Island.
  6. Click Refresh Visual.

  7. The new dendrogram visual appears.

  8. Change the title to NYC Taxi - Dendrogram.

    • Click (pencil icon) next to the title of the visualization to edit it, and enter the new name.

    • [Optional] Click (pencil icon) below the title of the visualization to add a brief description of the visual.

  9. At the top left corner of the Visual Designer, click Save.

  10. At the top left corner of the Visual Designer, click Close.

To adjust the dendrogram display, check all the available settings for this visual.