def install_pip(self, package, save=True, save_dev=False):
        """Installs a pip package.

        :param save: if `True`, pins the package to the Hydrogen requirements
            YAML file.
        :param save_dev: if `True`, pins the package as a development
            dependency to the Hydrogen requirements YAML file.
        :param return: a **single** :class:`Requirement` object, representing
            the installed version of the given package.
        """
        requirement = Requirement.coerce(package)
        click.echo("pip install " + requirement.package)
        cmd = envoy.run("pip install {}".format(str(requirement)))
        if cmd.status_code == 0:
            installed_packages = get_installed_pypackages()
            package = installed_packages[requirement.package]
            requirement.version = "=={}".format(package.version)
            if save:
                self.requirements["all"].add(requirement)
            if save_dev:
                self.requirements["dev"].add(requirement)
            if save or save_dev:
                self.requirements.save()
            return requirement
        else:
            fatal(cmd.std_err)
def transientsc(bch, title=''):
    """creates a transient short circuit plot"""
    cols = 1
    rows = 2
    htitle = 1.5 if title else 0
    fig, ax = plt.subplots(nrows=rows, ncols=cols,
                           figsize=(10, 3*rows + htitle))
    if title:
        fig.suptitle(title, fontsize=16)

    row = 1
    plt.subplot(rows, cols, row)
    ax = plt.gca()
    ax.set_title('Currents / A')
    ax.grid(True)
    for i in ('ia', 'ib', 'ic'):
        ax.plot(bch.scData['time'], bch.scData[i], label=i)
    ax.set_xlabel('Time / s')
    ax.legend()

    row = 2
    plt.subplot(rows, cols, row)
    ax = plt.gca()
    ax.set_title('Torque / Nm')
    ax.grid(True)
    ax.plot(bch.scData['time'], bch.scData['torque'])
    ax.set_xlabel('Time / s')

    fig.tight_layout(h_pad=2)
    if title:
        fig.subplots_adjust(top=0.92)