question: public ArrayRealVector ( double [ ] d , int pos , int size ) throws MathIllegalArgumentException , NullArgumentException { if ( d == null ) { throw new NullArgumentException ( ) ; } if ( d . length < pos + size ) { throw new MathIllegalArgumentException ( LocalizedCoreFormats . NUMBER_TOO_LARGE , pos + size , d . length ) ; } data = new double [ size ] ; System . arraycopy ( d , pos , data , 0 , size ) ; }
target:  Construct a vector from part of a array.