出于特定原因,我需要在 matplotlib 图例中显示垂直线。我试图让 matplotlib 明白我想要一条带有 lines.Line2D(x,y) 的垂直线,但这显然不起作用。
import matplotlib.pyplot as plt
from matplotlib import lines
fig, ax = plt.subplots()
ax.plot([0,0],[0,3])
lgd = []
lgd.append(lines.Line2D([0,0],[0,1], color = 'blue', label = 'Vertical line'))
plt.legend(handles = lgd)
我需要线条垂直显示,而不是图例。谁能帮忙?
制作 line2D 对象时可以使用垂直线标记。可以在here.
中找到有效标记列表import matplotlib.pyplot as plt
from matplotlib import lines
fig, ax = plt.subplots()
ax.plot([0,0],[0,3])
vertical_line = lines.Line2D([], [], color='#1f77b4', marker='|', linestyle='None',
markersize=10, markeredgewidth=1.5, label='Vertical line')
plt.legend(handles = [vertical_line])
plt.show()
如果目标是在图例中垂直标记而不是水平标记每条线,您可以通过
handler_map
. 更新图例句柄
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.legend_handler import HandlerLine2D
plt.plot([1,3,2], label='something')
plt.plot([.5,.5], [1,3], label='something else')
def update_prop(handle, orig):
handle.update_from(orig)
x,y = handle.get_data()
handle.set_data([np.mean(x)]*2, [0, 2*y[0]])
plt.legend(handler_map={plt.Line2D:HandlerLine2D(update_func=update_prop)})
plt.show()
如果目的是获得图例中绘制线的微型版本,原则上您可以使用此答案Using a miniature version of the plotting data as the legend handle。不过需要稍作修改以解决可能宽度为 0 的边界框,我现在也将其编辑到原始答案中。在这里,它看起来像:
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.legend_handler import HandlerLine2D
import matplotlib.path as mpath
from matplotlib.transforms import BboxTransformFrom, BboxTransformTo, Bbox
class HandlerMiniatureLine(HandlerLine2D):
def create_artists(self, legend, orig_handle,
xdescent, ydescent, width, height, fontsize,
trans):
legline, _ = HandlerLine2D.create_artists(self,legend, orig_handle,
xdescent, ydescent, width, height, fontsize, trans)
legline.set_data(*orig_handle.get_data())
ext = mpath.get_paths_extents([orig_handle.get_path()])
if ext.width == 0:
ext.x0 -= 0.1
ext.x1 += 0.1
bbox0 = BboxTransformFrom(ext)
bbox1 = BboxTransformTo(Bbox.from_bounds(xdescent, ydescent, width, height))
legline.set_transform(bbox0 + bbox1 + trans)
return legline,
plt.plot([1,3,2], label='something')
plt.plot([.5,.5], [1,3], label='something else')
plt.legend(handler_map={plt.Line2D:HandlerMiniatureLine()})
plt.show()