function loadTableGroupedByCategory(parent) {
   document.getElementById('divColorKey').style.display='none';
   var POLY_CAT=POLYHEDRA_BY_CATEGORY();

   for (i=0; i<POLY_CAT.length; i++) {
      var PC=POLY_CAT[i], code=PC.code;
      if (!categoryInFilter('category',code)) continue;
      var Color=PC.Color;
      var tr=document.createElement('tr'); parent.appendChild(tr);
      addCategoryHeader(tr,PC);
      loadDetailRows(PC.Polyhedra,parent,Color);
   }
}