add dimensions
        
        :parameter dimlist: list of dimensions
        :parameter dimvalues: list of values for dimlist

def add(self,dimlist,dimvalues):
        '''
        add dimensions
        
        :parameter dimlist: list of dimensions
        :parameter dimvalues: list of values for dimlist
        '''
        for i,d in enumerate(dimlist):
            self[d] = dimvalues[i]
        
        self.set_ndims()