I want to transform a table from a “wider” form (that’s convenient for editing) and other “longer” forms that are appropriate for different computations or displays. A use case is a project with multiple dates (e.g. proposal date, start date, completion date, report date). But more generally there is the general problem of pivoting a table where column headings become values in a column of a longer table.
Here’s an example where I’d like the second table to be derived formulaically from the first.