def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def winding_current(pos, current, ax=0):
    """plot winding currents"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Winding Currents / A')
    ax.grid(True)
    for p, i in zip(pos, current):
        ax.plot(p, i)