如何選擇一組線而不是僅一條線？

Question

我正在使用Matplolib的Line2D繪制多條線，並希望一次選擇或選擇所有線。

MWE提供的功能是繪制三角形（可以是任何多邊形或形狀），並包括一個功能，該功能可以分別拾取每條線。 我想通過單擊選擇整個三角形。 另外，我注意到，如果我添加另一行，onPick函數根本無法使用。 有人知道我做錯了嗎？

編輯按照下面的注釋中的建議，我添加了一個Polygon和一個修改后的函數pick_simple（）（來自： https ://matplotlib.org/3.1.0/gallery/event_handling/pick_event_demo.html）。 但是不幸的是，這帶來了新的問題。 通過繪制多邊形，即使我設置fill = False以及線寬和顏色，我也會得到一個填充的藍色補丁。 而且pick_simple（）函數沒有做任何讓我感到困惑的事情。

from matplotlib import pyplot as plt
from matplotlib.lines import Line2D
from matplotlib.patches import Polygon
from matplotlib.collections import PatchCollection


fig = plt.figure()
ax = fig.add_subplot(111)

triangle = [[0.1, 0.3],
            [0.2, 0.8],
            [0.3, 0.5],
            [0.1, 0.3]]

for i in range(len(triangle)-1):
    tri = Line2D([triangle[i][0],triangle[i+1][0]],[triangle[i][1],
            triangle[i+1][1]], linewidth=0.75, color='#F97306')
    tri.set_picker(True)
    ax.add_line(tri)

geometry = [[0.0,0.0],[0.1,0.05],[0.2,0.15],[0.3,0.20],[0.4,0.25],[0.5,0.30],
        [0.6,0.25],[0.7,0.15],[0.8,0.05],[0.9,0.025],[1.0,0.0]]

patches = []
polygon = Polygon(geometry, closed=False, fill=False, linewidth=0.75, color='#F97306')
polygon.set_picker(True)
patches.append(polygon)
p = PatchCollection(patches)
ax.add_collection(p)


plt.show()

def pick_simple():
    def onpick(event):
        if isinstance(event.artist, Polygon):
            patch = event.artist
            print('onpick patch:', patch.get_path())
    fig.canvas.mpl_connect('pick_event', onpick)

def pick_factory(ax):
    def onPick(event):
        if event.inaxes == ax:
            for line in ax.lines:
                if line.get_picker():
                    cont, ind = line.contains(event)
                    if cont:
                        line.set_color('#029386')
                        line.set_linewidth(5)
                        ax.figure.canvas.draw_idle()

    fig = ax.get_figure() # get the figure of interest
    fig.canvas.mpl_connect('button_press_event', onPick)

pick_factory(ax)
pick_simple()

Answer 1

有幾個較小的錯誤。

• 要選擇某個集合的成員，您需要將選擇器設置為該集合，而不是初始藝術家。 因此，pick回調需要通過event.ind選擇被選擇的集合的成員。
• PatchCollection的目的通常是設置其子級本身的屬性，如線寬，顏色等。 如果您不想這樣做，則需要使用match_original=True

完整的代碼：

from matplotlib import pyplot as plt
from matplotlib.patches import Polygon
from matplotlib.collections import PatchCollection


fig = plt.figure()
ax = fig.add_subplot(111)


geometry = [[0.0,0.0],[0.1,0.05],[0.2,0.15],[0.3,0.20],[0.4,0.25],[0.5,0.30],
        [0.6,0.25],[0.7,0.15],[0.8,0.05],[0.9,0.025],[1.0,0.0]]

patches = []
polygon = Polygon(geometry, closed=False, fill=False, linewidth=3, color='#F97306')
patches.append(polygon)
p = PatchCollection(patches, match_original=True)
p.set_picker(True)
ax.add_collection(p)


def pick_simple():
    def onpick(event):
        if isinstance(event.artist, PatchCollection):
            collection = event.artist
            print('onpick collection:', collection)
            print('picked index', event.ind)
            print('path at index', collection.get_paths()[event.ind[0]])
    return fig.canvas.mpl_connect('pick_event', onpick)


cid = pick_simple()
plt.show()