def install(h, pip, groups, save, save_dev, packages):
    """Install a pip or bower package."""
    if groups:
        groups = [text_type.strip(group) for group in groups.split(",")]
    else:
        groups = h.requirements.keys()

    if not packages:
        for group in groups:
            if group not in h.requirements:
                warning("{} not in requirements".format(group))
                continue
            install = (h.install_bower if group.startswith("bower")
                       else h.install_pip)
            for requirement in h.requirements[group]:
                install(str(requirement), save=False, save_dev=False)
    if pip:
        for package in packages:
            h.install_pip(package, save=save, save_dev=save_dev)
    else:
        for package in packages:
            h.install_bower(package, save=save, save_dev=save_dev)
def mmf(f, title='', ax=0):
    """plot magnetomotive force (mmf) of winding"""
    if ax == 0:
        ax = plt.gca()
    if title:
        ax.set_title(title)
    ax.plot(np.array(f['pos'])/np.pi*180, f['mmf'])
    ax.plot(np.array(f['pos_fft'])/np.pi*180, f['mmf_fft'])
    ax.set_xlabel('Position / Deg')

    phi = [f['alfa0']/np.pi*180, f['alfa0']/np.pi*180]
    y = [min(f['mmf_fft']), 1.1*max(f['mmf_fft'])]
    ax.plot(phi, y, '--')
    alfa0 = round(f['alfa0']/np.pi*180, 3)
    ax.text(phi[0]/2, y[0]+0.05, f"{alfa0}°",
            ha="center", va="bottom")
    ax.annotate(f"", xy=(phi[0], y[0]),
                xytext=(0, y[0]), arrowprops=dict(arrowstyle="->"))
    ax.grid()