def freeze(h, output_yaml, resolve, groups):
    """Output installed packages."""
    if not groups:
        groups = filter(lambda group: not group.lower().startswith("bower"),
                        h.requirements.keys())
    else:
        groups = [text_type.strip(group) for group in groups.split(",")]

    if output_yaml:
        for requirements in h.requirements.values():
            for requirement in requirements:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
        click.echo(h.requirements.yaml)
    else:
        for group in groups:
            if not h.requirements[group]:
                continue
            click.echo("# {}".format(group))
            for requirement in h.requirements[group]:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
                click.echo(str(requirement))
def _plot_surface(ax, x, y, z, labels, azim=None):
    """helper function for surface plots"""
    # ax.tick_params(axis='both', which='major', pad=-3)
    assert np.size(x) > 1 and np.size(y) > 1 and np.size(z) > 1
    if azim is not None:
        ax.azim = azim
    X, Y = np.meshgrid(x, y)
    Z = np.ma.masked_invalid(z)
    ax.plot_surface(X, Y, Z,
                    rstride=1, cstride=1,
                    cmap=cm.viridis, alpha=0.85,
                    vmin=np.nanmin(z), vmax=np.nanmax(z),
                    linewidth=0, antialiased=True)