在传奇 Python Matplotlib 中仅显示某些项

我目前正在绘制一个堆叠的条形图，其中包含大量的分类学数据，并且只希望显示图例中的重要物种(在约500个图例中，我希望显示约25个)。有什么简单的方法吗？下面是我的代码:

labels=['0','20','40','60','80','100','120']
ax1=subj1df.plot(kind='barh', stacked=True,legend=True,cmap='Paired', grid=False)
legend(ncol=2,loc=2, bbox_to_anchor=(1.05, 1), borderaxespad=0.)
label1=['Baseline','8h','24h','48h','96h','120h']
ax1.set_yticklabels(label1, fontdict=None, minor=False)
plt.title('Subject 1 Phyla',fontweight='bold')
plt.savefig('Subject1Phyla.eps', format='eps', dpi=1000)
ax1.set_xticklabels(labels)

编辑: 试图添加这个只显示一个图例条目，但是只返回一个空图例:

h, l = ax1.get_legend_handles_labels()
legend(l[4],h[4],ncol=2,loc=2, bbox_to_anchor=(1.05, 1), borderaxespad=0.)
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最佳答案

I often insert an empty label for legends I don't want to show. I made an extremely simple example which I hope will help you. You will need to tweak this to your own data but the elements you need should be there. 

import matplotlib.pyplot as plt
import numpy as np


myY=np.random.randint(20, size=10)
myX=np.arange(0,len(myY))


selected=[5,10,15]


fig = plt.figure()
for X,Y in zip(myX,myY):
if Y in selected:
mylabel="label = %s"%(Y); mycolor='blue'
else:
mylabel=None; mycolor='red'
plt.scatter(X,Y,50, color=mycolor, label=mylabel)
plt.legend()
plt.show()

This creates the following plot: enter image description here

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This works:

plt.plot(x, y, label='_nolegend_')

source

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For whatever reason both answers didn't work for mine situation. What worked, and actually was indicated above:

legend also takes a list of artists and a list of labels to precisely control what goes into your legend – tacaswell Jul 11 '14 at 4:46

import pandas as pd
import matplotlib.pyplot as plt
import pylab


pd.Series(range(10)).plot(color = 'grey')
x = list(range(10))
y = [i + 1 for i in x]
scat1 = plt.scatter(x, y)


pylab.legend([scat1],['moved points'], loc = 'upper left')


plt.show()

The result of the code: The result of the code:

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You can also use an empty string variable:

    plt.plot(xData, yData, ..., label=str())

By passing an empty str() object, it doesn't write down anything.

Matplotlib API reference

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I know this post is coming up on a decade old, but I was looking for a way to do something similar and this post was on top of the google results. I was working with data tracking heap usage of a process and the processes that it spawned. Most of the processes used up a negligible amount of memory, and displaying the entire legend would have been unwieldy. I ended up with the following solution:

label_names = heap_df.columns.values.tolist()
max_per_proc = heap_df.max()
max_heap_overall = max(max_per_proc)


fig, ax = plt.subplots()
plt.stackplot(heap_df.index, heap_df.values.T, labels=label_names)
lines, labels = ax.get_legend_handles_labels()
lbl_idx = []
for idx in range(len(labels)):
if max_per_proc[labels[idx]] / max_heap_overall > 0.01:
lbl_idx.append(idx)
ax.legend([lines[i] for i in lbl_idx], [labels[i] for i in lbl_idx])
        

plt.show()

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