def w(self, value):
self._w = is_number(value)
def J(self, value):
self._J = is_number(value)
def vb(self, value):
self._vb = is_number(value)
def va(self, value):
self._va = is_number(value)
def wb(self, value):
self._wb = is_number(value)
def wa(self, value):
self._wa = is_number(value)
