public void append(double key,int val){
  if (size == keys.length) {
    keys=Arrays.copyOf(keys,size << 1);
    vals=Arrays.copyOf(vals,size << 1);
  }
  keys[size]=key;
  vals[size]=val;
  ++size;
}

public void append ( double key , int val ) { if ( size == keys . length ) { keys = Arrays . copyOf ( keys , size << 1 ) ; vals = Arrays . copyOf ( vals , size << 1 ) ; } keys [ size ] = key ; vals [ size ] = val ; ++ size ; }
append a key - value pair .
