question: private static void s_uaColSumEqNe ( MatrixBlock in , MatrixBlock out , double [ ] bv , BinaryOperator bOp ) throws DMLRuntimeException { int agg0 = sumEqNe ( 0.0 , bv , bOp ) ; out . allocateDenseBlock ( true ) ; Arrays . fill ( out . getDenseBlock ( ) , 0 , out . getNumColumns ( ) , agg0 ) ; if ( agg0 != 0.0 ) out . setNonZeros ( out . getNumColumns ( ) ) ; if ( in . isEmptyBlock ( false ) ) return ; SparseBlock sblock = in . getSparseBlock ( ) ; for ( int j = 0 ; j < sblock . numRows ( ) ; j ++ ) if ( ! sblock . isEmpty ( j ) ) { int apos = sblock . pos ( j ) ; int alen = sblock . size ( j ) ; int [ ] aix = sblock . indexes ( j ) ; double [ ] avals = sblock . values ( j ) ; for ( int i = apos ; i < apos + alen ; i ++ ) { int cnt = sumEqNe ( avals [ i ] , bv , bOp ) ; out . quickSetValue ( 0 , aix [ i ] , cnt ) ; } } }
target:  UAgg colSums Sparse Matrix for Equal and NotEqual operator 