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 forcedens_fft(title, fdens, ax=0):
    """plot force densities FFT
    Args:
      title: plot title
      fdens: force density object
    """
    if ax == 0:
        ax = plt.axes(projection="3d")

    F = 1e-3*fdens.fft()
    fmin = 0.2
    num_bars = F.shape[0] + 1
    _xx, _yy = np.meshgrid(np.arange(1, num_bars),
                           np.arange(1, num_bars))
    z_size = F[F > fmin]
    x_pos, y_pos = _xx[F > fmin], _yy[F > fmin]
    z_pos = np.zeros_like(z_size)
    x_size = 2
    y_size = 2

    ax.bar3d(x_pos, y_pos, z_pos, x_size, y_size, z_size)
    ax.view_init(azim=120)
    ax.set_xlim(0, num_bars+1)
    ax.set_ylim(0, num_bars+1)
    ax.set_title(title)
    ax.set_xlabel('M')
    ax.set_ylabel('N')
    ax.set_zlabel('kN/m²')