Plot means with confidence (stderr or other metric) bands in a pretty format using matplotlib.

plot_with_bands.py

def plot_with_bands(graph_title, means, bands, series, xvals=None, xlabel=None, ylabel=None, subtitle=None, filename='results.pdf'):
    colors = ['blue','red','green', 'black', 'yellow', 'orange', 'purple', 'brown'] # max 8 lines
    print 'means: {0} bands: {1}'.format(means.shape, bands.shape)
    assert(means.shape == bands.shape)
    assert(xvals is None or xvals.shape[0] == means.shape[1])
    assert(means.shape[1] <= len(colors))
    if xvals is None:
        xvals = np.arange(means.shape[0])
    ax = plt.subplot(111)
    plt.ticklabel_format(axis='y', style='plain', useOffset=False)
    for i,mean in enumerate(means):
        print 'plotting {0}'.format(mean)
        plt.plot(xvals, mean, label=series[i], color=colors[i])
        plt.fill_between(xvals, mean + bands[i], mean - bands[i], facecolor=colors[i], alpha=0.2)
    if xlabel is not None:
        plt.xlabel(xlabel)
    if ylabel is not None:
        plt.ylabel(ylabel)
    if subtitle is not None:
        plt.title('{0}\n{1}'.format(graph_title, subtitle))
    else:
        plt.title('{0}'.format(graph_title))
    # Shink current axis by 20%
    box = ax.get_position()
    ax.set_position([box.x0, box.y0, box.width * 0.8, box.height])
    # Put a legend to the right of the current axis
    ax.legend(loc='center left', bbox_to_anchor=(1, 0.5))
    plt.savefig(filename)