def loads(self, requirements_text):
        lines = re.findall(Requirement.spec_regex,
                           requirements_text,
                           re.MULTILINE)
        for line in lines:
            self.add(Requirement(line[0], "".join(line[1:])))
def idq_ld(id, iq, ld, ax=0):
    """creates a surface plot of ld vs. id, iq"""
    if ax == 0:
        _create_3d_axis()
        ax = plt.gca()
    _plot_surface(ax, id, iq, np.asarray(ld)*1e3,
                  (u'Id/A', u'Iq/A', u'L d/mH'),
                  azim=120)