How to Create an Arc Diagram

What is an Arc Diagram

The graphs below show all possible links between the values selected from two similar columns, using multiple Line Charts. For instance, one column may have Employee names, and the other one Manager names. Managers are also Employees.

Remark the graphs are bidirectional, and a link from a to b is displayed the same way as the link from b to a. The graphs do not show hierarchies, but bidirectional dependencies.

In Labeled Arc Diagrams, axis labels appear as node names. Hide them, and half of the arcs will appear below the nodes, as in the last two diagrams.

Steps to Create an Arc Diagram

Start Visual Xtractor or Data Xtractor. Connect to a database. Create or design a SQL query. Run the query and check the results.

1. Display and enable the Chart query builder.
2. Select the column with independent values as chart Label.
3. Select some other column with similar and related values as Line Charts – Arc Line.
4. You may also select another column as chart Category, to have different node colors.
5. Hide the axis node labels, to have half of the arcs below the nodes.

Labeled Arc Diagram Demo Query

This is a great alternative to learn about and play with this type of chart, if you don’t want to create it from scratch.

Look for this ready-to-use generated query under the Queries > Demo Queries > Charts > Cartesian Charts folder. Click on the “add demo queries” command link, if Arc Diagram demo query is not already there.

The generated demo queries must work for any database, with no restriction. They use constant values generated on-the-fly and your database SQL engine, but do not depend on data from your tables, and never alter your database in any way.

Arc Diagram with Category

You may select another column as chart Category, in which case the chart legend will be populated with category items. A multi-color Arc Diagram with Category will show all nodes of a category item with the same color. This makes it easy to select only those items to be displayed.

Look for the ready-to-use Arcs with Category Chart generated demo query under the Queries > Demo Queries > Charts > Category Charts folder. Click on the “add demo queries” command link, if the demo query is not already there.

Customize your Arc Diagram

The chart toolbar at the bottom has many options you may change with one single click, to alter the graph. Here is just an example of what you can further do with this type of chart:

1. Make it multi-color, to use one different color for each node.
2. Show default (straight) lines and dot line styles.
3. Change the chart theme (to Sand Signika).
4. Hide all chart labels, so arcs between nodes could also appear below.
5. Display square point markers.
6. Click on legend items to hide some lines.

Conclusion

• Creating Arc Diagrams in Data Xtractor or Visual Xtractor is fast, simple and trivial: declare one independent column as Label, and another related similar column, with the same kind of data, as Arc Line, and that’s it!
• Add a chart Category column, to filter all nodes that belong to category items.
• Hide the axis labels to show arcs between nodes above and below. In Labeled Arc Diagrams, with axis labels (by default), the arcs appear only above the nodes.
• Many builtin powerful features of these chart type are common to most other charts: filtering series through the legend items, interactivity, monochrome or grayscale colors etc.
• Switch to another builtin chart theme, or customize your own, for any possible color or other styles.