def METHOD_NAME(self, locs):
    """Compute displacement field at locations.
    """
    strain = self.strain(locs)
    (npts, dim) = locs.shape
    disp = numpy.zeros((1, npts, self.SPACE_DIM), dtype=numpy.float64)
    disp[:,:, 2] = p_density * gacc / (p_lambda + 2 * p_mu) * \
        (0.5 * (locs[:, 2]**2 - zmin**2) - zmax * (locs[:, 2] - zmin))
    return disp