pub fn getpivotdata(
sheets: &[&Sheet],
pivot: &PivotTable,
data_field: &str,
criteria: &[(String, String)],
) -> Result<ResultData, String>Expand description
Implements GETPIVOTDATA: extracts a single summarized value out of a
pivot table’s computed grid by data-field name plus (row/col field, item) criteria pairs, the same way real Excel’s formula does when
pointed at a rendered pivot. Recomputes the grid fresh from sheets
rather than caching it, consistent with formulas re-evaluating from
current sheet state on every recalculation pass.