protected static < A > int [ ] sortedIndex ( final NumberArrayAdapter < ? , A > adapter , final A data , int len ) { int [ ] s1 = MathUtil . sequence ( 0 , len ) ; IntegerArrayQuickSort . sort ( s1 , ( x , y ) -> Double . compare ( adapter . getDouble ( data , x ) , adapter . getDouble ( data , y ) ) ) ; return s1 ; }
Build a sorted index of objects .