*/
public static double getArea(ArrayList<Region> regs, Region tarr) throws RegionException{
double area=0;
for( int i=0; i<regs.size() ; i++ ){
Region r= (Region)regs.get(i);
if(r.overlapsWith(tarr)){
double at= (double)r.attr;
area+= (r.getOverlapRegion(tarr).getRange()+1) * at;
}
}
return area;