我试图在matplotlib的情节之外放置一个相当广泛的传奇.这个图例有很多条目,每个条目都可以很长(但我不确切知道多长时间).
显然,这很容易使用
legendHandle = plt.legend(loc = "center left", bbox_to_anchor = (1, 0.5))
但问题是图例被窗户边缘切断了.我花了很长时间寻找解决方案.到目前为止我能找到的最好的事情是:
box = ax.get_position()
ax.set_position([box.x0, box.y0, box.width * 0.8, box.height])
plt.legend(loc = "center left", bbox_to_anchor = (1, 0.5))
不幸的是,这并没有真正解决我的问题.由于应用于框宽的显式因子0.8,这仅适用于图形和图例宽度的一个特定组合.如果我调整图形窗口的大小,或者我的图例条目具有不同的长度,则它不起作用.
我只是不明白如何在图中放置一个图例是如此困难.我习惯了Matlab,就像它一样简单
legend('Location', 'eastoutside')
Python中是否有类似的东西我缺少?
最佳答案 尝试了很多,这是我能想到的最好的:
from matplotlib.lines import Line2D
from matplotlib.gridspec import GridSpec
from enum import Enum
class Location(Enum):
EastOutside = 1
WestOutside = 2
NorthOutside = 3
SouthOutside = 4
class Legend:
def __init__(self, figure, plotAxes, location: Location):
self.figure = figure
self.plotAxes = plotAxes
self.location = location
# Create a separate subplot for the legend. Actual location doesn't matter - will be modified anyway.
self.legendAxes = figure.add_subplot(1, 2, 1)
self.legendAxes.clear() # remove old lines
self.legendAxes.set_axis_off()
# Add all lines from the plot to the legend subplot
for line in plotAxes.get_lines():
legendLine = Line2D([], [])
legendLine.update_from(line)
self.legendAxes.add_line(legendLine)
if self.location == Location.EastOutside:
self.legend = self.legendAxes.legend(loc = "center left")
elif self.location == Location.WestOutside:
self.legend = self.legendAxes.legend(loc = "center right")
elif self.location == Location.NorthOutside:
self.legend = self.legendAxes.legend(loc = "lower center")
elif self.location == Location.SouthOutside:
self.legend = self.legendAxes.legend(loc = "upper center")
else:
raise Exception("Unknown legend location.")
self.UpdateSize()
# Recalculate legend size if the size changes
figure.canvas.mpl_connect('resize_event', lambda event: self.UpdateSize())
def UpdateSize(self):
self.figure.canvas.draw() # draw everything once in order to get correct legend size
# Extract legend size in percentage of the figure width
legendSize = self.legend.get_window_extent().inverse_transformed(self.figure.transFigure)
legendWidth = legendSize.width
legendHeight = legendSize.height
# Update subplot such that it is only as large as the legend
if self.location == Location.EastOutside:
gridspec = GridSpec(1, 2, width_ratios = [1 - legendWidth, legendWidth])
legendLocation = 1
plotLocation = 0
elif self.location == Location.WestOutside:
gridspec = GridSpec(1, 2, width_ratios = [legendWidth, 1 - legendWidth])
legendLocation = 0
plotLocation = 1
elif self.location == Location.NorthOutside:
gridspec = GridSpec(2, 1, height_ratios = [legendHeight, 1 - legendHeight])
legendLocation = 0
plotLocation = 1
elif self.location == Location.SouthOutside:
gridspec = GridSpec(2, 1, height_ratios = [1 - legendHeight, legendHeight])
legendLocation = 1
plotLocation = 0
else:
raise Exception("Unknown legend location.")
self.legendAxes.set_position(gridspec[legendLocation].get_position(self.figure))
self.legendAxes.set_subplotspec(gridspec[legendLocation]) # to make figure.tight_layout() work if that's desired
self.plotAxes.set_position(gridspec[plotLocation].get_position(self.figure))
self.plotAxes.set_subplotspec(gridspec[plotLocation]) # to make figure.tight_layout() work if that's desired
在我到目前为止测试的情况下,这使得图例或多或少都没有.用法是例如
import matplotlib.pyplot as plt
plt.ion()
figure = plt.figure()
plotAxes = figure.gca()
plotAxes.plot([1, 2, 3], [4, 5, 6], "b-", label = "Testaaaaaaaaaaaaaa 1")
plotAxes.plot([1, 2, 3], [6, 5, 4], "r-", label = "Test 2")
legend = Legend(figure, plotAxes, Location.EastOutside)
让我问一下我在评论中发布的问题……我将如何建议将其作为matplotlib开发人员的附加功能? (不是我的黑客,而是在图中有传说的本地方式)