线条样式

简单的线条样式可以通过字符串 "solid"、"dotted"、"dashed" 或 "dashdot" 来定义。更精细的控制可以通过提供一个破折号元组 (offset, (on_off_seq)) 来实现。例如，(0, (3, 10, 1, 15)) 表示（3pt 线，10pt 空格，1pt 线，15pt 空格）且无偏移，而 (5, (10, 3)) 表示（10pt 线，3pt 空格），但跳过前 5pt 线。另请参阅 Line2D.set_linestyle。

注意：破折号样式也可以通过 Line2D.set_dashes 进行配置，如 虚线样式配置 所示，并使用关键字 dashes 将破折号序列列表传递给 property_cycle 中的循环器。

import matplotlib.pyplot as plt
import numpy as np

linestyle_str = [
     ('solid', 'solid'),      # Same as (0, ()) or '-'
     ('dotted', 'dotted'),    # Same as (0, (1, 1)) or ':'
     ('dashed', 'dashed'),    # Same as '--'
     ('dashdot', 'dashdot')]  # Same as '-.'

linestyle_tuple = [
     ('loosely dotted',        (0, (1, 10))),
     ('dotted',                (0, (1, 1))),
     ('densely dotted',        (0, (1, 1))),
     ('long dash with offset', (5, (10, 3))),
     ('loosely dashed',        (0, (5, 10))),
     ('dashed',                (0, (5, 5))),
     ('densely dashed',        (0, (5, 1))),

     ('loosely dashdotted',    (0, (3, 10, 1, 10))),
     ('dashdotted',            (0, (3, 5, 1, 5))),
     ('densely dashdotted',    (0, (3, 1, 1, 1))),

     ('dashdotdotted',         (0, (3, 5, 1, 5, 1, 5))),
     ('loosely dashdotdotted', (0, (3, 10, 1, 10, 1, 10))),
     ('densely dashdotdotted', (0, (3, 1, 1, 1, 1, 1)))]


def plot_linestyles(ax, linestyles, title):
    X, Y = np.linspace(0, 100, 10), np.zeros(10)
    yticklabels = []

    for i, (name, linestyle) in enumerate(linestyles):
        ax.plot(X, Y+i, linestyle=linestyle, linewidth=1.5, color='black')
        yticklabels.append(name)

    ax.set_title(title)
    ax.set(ylim=(-0.5, len(linestyles)-0.5),
           yticks=np.arange(len(linestyles)),
           yticklabels=yticklabels)
    ax.tick_params(left=False, bottom=False, labelbottom=False)
    ax.spines[:].set_visible(False)

    # For each line style, add a text annotation with a small offset from
    # the reference point (0 in Axes coords, y tick value in Data coords).
    for i, (name, linestyle) in enumerate(linestyles):
        ax.annotate(repr(linestyle),
                    xy=(0.0, i), xycoords=ax.get_yaxis_transform(),
                    xytext=(-6, -12), textcoords='offset points',
                    color="blue", fontsize=8, ha="right", family="monospace")


fig, (ax0, ax1) = plt.subplots(2, 1, figsize=(10, 8), height_ratios=[1, 3])

plot_linestyles(ax0, linestyle_str[::-1], title='Named linestyles')
plot_linestyles(ax1, linestyle_tuple[::-1], title='Parametrized linestyles')

plt.tight_layout()
plt.show()