Change main plot legend label text

Question

So far I have been able to label the subplots just fine but I'm having an issue with the main one.

Here's the relevant part of my code:

data_BS_P = data[channels[0]]
data_BS_R = data[channels[1]]
data_BS_Y = data[channels[2]]
plot_BS_P = data_BS_P.plot() #data_BS_P is a pandas dataframe
axBS = plot_BS_P.gca()
axBS.plot(data_BS_R, label='Roll')
axBS.plot(data_BS_Y, label='Yaw')
axBS.set_ylabel('Amplitude (urad)')
axBS.legend(loc='upper center', bbox_to_anchor=(0.5, 1.05), ncol=3,
            fancybox=True, shadow=True)
ml1 = MultipleLocator(10)
ml2 = MultipleLocator(3600)
axBS.yaxis.set_minor_locator(ml1)
axBS.xaxis.set_minor_locator(ml2)
plot_BS_P.save('L1-SUS-BS_M1_DAMP_PRY_INMON.jpg')

And this is what I have so far: enter image description here Notice the lengthy label for the blue line. I'd like that to be labeled as "Pitch" instead of the file name. In which line can I do that?

You haven't posted enough code to solve this problem. Post the code where the blue line is plotted. I assume the problem is in this line `plot_BS_P = data_BS_P.plot()`. — ebarr, Apr 13 '14 at 00:06
@ebarr, `plot_BS_P = data_BS_P.plot()` did it. `data_BS_P` is likely a `pandas` `DataFrame`, which has it own name blot-in. Am I right, O.P.? — CT Zhu, Apr 13 '14 at 00:11
It's the data_BS_P.plot() that plots the blue line. The line above this is data = TimeSeriesDict.fetch(channels, start, end, verbose=True) and the rest is the massive list of channels I have to download... — N.K., Apr 13 '14 at 00:20

score 108 · Answer 1 · answered Feb 14 '16 at 03:35

108

Another way:

ax.legend(labels=mylabels)

answered Feb 14 '16 at 03:35

Kamil Sindi

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7

This was by far the easiest way presented here for my use case. Thank you. – KobeJohn Apr 13 '16 at 05:08
2

equivalently, if ax isn't explicitly defined then of course plt.legend(labels=my_labels) where my_labels is a list. – Quetzalcoatl Aug 17 '18 at 22:37
13

This broke the legend patch colors when used on boxplots made with seaborn. – rovyko Apr 11 '19 at 21:03
1

I used it but it does not preserve the colors I don't know why... – Mehdi Golzadeh Nov 06 '19 at 14:15
how to pass a dictionary ? seems not to work, i don't how which is the order of classes... – user305883 Sep 07 '22 at 20:08
It provides the proper labels, but colors instead completely disappeared. – Yustina Ivanova Oct 02 '22 at 15:10

score 95 · Accepted Answer · answered Apr 13 '14 at 00:07

95

You need to gain access of the legend() object and use set_text() to change the text values, a simple example:

plt.plot(range(10), label='Some very long label')
plt.plot(range(1,11), label='Short label')
L=plt.legend()
L.get_texts()[0].set_text('make it short')
plt.savefig('temp.png')

enter image description here

In your case, you are changing the first item in the legend, I am quite sure the 0 index in L.get_texts()[0] applies to your problem too.

answered Apr 13 '14 at 00:07

CT Zhu

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In interactive mode, add `plt.gcf().canvas.draw()` to redraw the figure with the new label. (In the provided example, `plt.savefig` updates the figure before it is saved.) – Arcturus B Mar 05 '19 at 08:38
a bit shorter : `L.texts[0]..set_text('shorter')` – 2diabolos.com Feb 25 '21 at 12:19
Can't get this to work with `xarray.DataArray.plot.line()` – climatestudent Mar 04 '22 at 18:52

score 4 · Answer 3 · answered Nov 12 '19 at 16:28

The answer by ksindi works for setting the labels, but as some others commented, it can break the legend colours when used with seaborn (in my case a scatterplot: the dots and text didn't line up properly anymore). To solve this, also pass the handles to ax.legend.

# the legend has often numbers like '0.450000007', the following snippet turns those in '0.45'
label_list = []
for t in ax.get_legend_handles_labels():
    # the first result will be all handles, i.e. the dots in the legend
    # the second result will be all legend text
    label_list.append(t)

new_list = []
for txt in label_list[1]:
    if txt[0] == '0':
        txt = str(txt)[:4]
    new_list.append(txt)
label_list[1] = new_list

ax.legend(handles=label_list[0], labels=label_list[1])

(I would have posted this as a comment, but don't have enough reputation yet)

score 1 · Answer 4 · answered Jul 26 '23 at 11:54

1

To avoid messing up color and marker size of the legend keys when plotting with seaborn:

handles, previous_labels = ax.get_legend_handles_labels()
ax.legend(handles=handles, labels=new_labels)

answered Jul 26 '23 at 11:54

angelo-peronio

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Change main plot legend label text

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