Timeline renderer for temporal data

[thinkh]

Use Case

@ngehlenborg described this use case in the context of clinical data. They want to stratify the table by PatientId (which is treated as categorical attribute) and then aggregate the groups. Every record (row) has a date attribute they need an adequate group representation.

Available Functionality

I saw that there is a DateColumn available. Since this column is treated as ValueColumn it can only be displayed as string.

Feature Request

I suggest the following date renderer:

Item renderer

• Date will be rendered as String
• The user can switch the date format in a new dialog (accessible from the more menu)

Group renderer

• Set ticks or points for every timepoint (row) similar to a timeline
• Normalize over all values from the column

Additional Column Dialogs

• Switch displayed date format
• Stratify by... [hour|day|week|month|year]

Allow Impose Functionality
It should be possible to impose this timeline render (i.e. Imposition Column), so that the timepoints can be colored by categorical data or change the size for numerical data