def METHOD_NAME(self, x, y, z):
    """
    Set the shape for all planes
    :param int x: the size of the data set in x direction
    :param int y: the size of the data set in y direction
    :param int z: the size of the data set in z direction
    """
    x -= 1
    y -= 1
    z -= 1
    self._max = x, y, z
    self._x.setSize(0, y, z)
    self._y.setSize(x, 0, z)
    self._z.setSize(x, y, 0)
    self._xx.setSize(x, 0, 0)
    self._yy.setSize(0, y, 0)
    self._zz.setSize(0, 0, z)