Dumbbell plot

Description

Dumbbell plot [1] (also known as Dumbbell chart, Connected dot plot) is great for displaying changes between two points in time, two conditions or differences between two groups.

Example:

Pointers

• Ideally, you start prototyping in a scripting or notebook environment where you can iterate fast. installation instructions can be found here: https://plotly.net/#Installation
• Charts like this that are using baseline trace types to create a new chart type should only be implemented in the top-level Chart API. An example where this is already done is the Range chart that combines a set of differently styled line charts.
• When possible, use #IConvertible for data input, as this allows for strings, number types such as int and float, and DateTime.

References

• [1] https://datavizproject.com/data-type/dumbbell-plot/

Start in src/Plotly.NET/ChartAPI/Chart2D.fs, especially the Chart.Range implementation referenced by the issue. Prototype the chart in a scripting or notebook environment using the Plotly.NET installation instructions, and review how baseline line charts are combined. Done means a high-level Dumbbell chart API is available with flexible #IConvertible inputs and displays the two-point connections described in the issue.