question: private void assertArrayEquals ( double [ ] expected , double [ ] actual , double delta , boolean checkNaN ) { Assert . assertEquals ( expected . length , actual . length ) ; for ( int index = 0 ; index < actual . length ; index ++ ) { double d1 = expected [ index ] ; double d2 = actual [ index ] ; if ( Double . isNaN ( d1 ) || Double . isNaN ( d2 ) ) { if ( checkNaN ) { Assert . assertTrue ( Double . isNaN ( d1 ) == Double . isNaN ( d2 ) ) ; } Assert . assertTrue ( true ) ; } else { Assert . assertEquals ( d1 , d2 , delta ) ; } } }
target:  This is an assertion for a special case when a loss full algorithm is used and a quantification with null checks. The will result in wrong null values, because some of the values representing blank will be lost.