question: private DoubleMinMax exactMinMax ( Relation < O > relation , DistanceQuery < O > distFunc ) { final FiniteProgress progress = LOG . isVerbose ( ) ? new FiniteProgress ( "Exact fitting distance computations" , relation . size ( ) , LOG ) : null ; DoubleMinMax minmax = new DoubleMinMax ( ) ; for ( DBIDIter iditer = relation . iterDBIDs ( ) ; iditer . valid ( ) ; iditer . advance ( ) ) { for ( DBIDIter iditer2 = relation . iterDBIDs ( ) ; iditer2 . valid ( ) ; iditer2 . advance ( ) ) { if ( DBIDUtil . equal ( iditer , iditer2 ) ) { continue ; } double d = distFunc . distance ( iditer , iditer2 ) ; minmax . put ( d ) ; } LOG . incrementProcessed ( progress ) ; } LOG . ensureCompleted ( progress ) ; return minmax ; }
target:  Compute the exact maximum and minimum.