question: private boolean [ ] defineIrrelevant ( Random random ) { boolean [ ] irr = new boolean [ getNumAttributes ( ) ] ; for ( int i = 0 ; i < irr . length ; i ++ ) { irr [ i ] = false ; } int numIrr = 0 ; for ( int i = 0 ; ( numIrr < getNumIrrelevant ( ) ) && ( i < getNumAttributes ( ) * 5 ) ; i ++ ) { int maybeNext = ( int ) ( random . nextDouble ( ) * irr . length ) ; if ( irr [ maybeNext ] == false ) { irr [ maybeNext ] = true ; numIrr ++ ; } } return irr ; }
target:  Defines randomly the attributes as irrelevant. Number of attributes to be set as irrelevant is either set with a preceeding call of setNumIrrelevant() or is per default 0.