The heatmap panel provides a heat map for representing pivot facet counts.
The Panel tab defines what data is displayed in the panel and how it is displayed.
Row Field: The field from Solr that will provide data for rows.
Column Field: The field from Solr that will provide data for columns.
Rows Limit: The maximum number of rows to display.
Heatmap Color: The base color for the heatmap. The intensity of the color in any cell is proportional to the pivot facet count for that cell.