Wie kann ich in matplotlib eine leere Nebenhandlung erstellen?

84

Ich mache eine Gruppe von Unterplots (z. B. 3 x 2) in matplotlib, aber ich habe weniger als 6 Datensätze. Wie kann ich die verbleibende Nebenhandlung leer machen?

Das Arrangement sieht so aus:

+----+----+
| 0,0| 0,1|
+----+----+
| 1,0| 1,1|
+----+----+
| 2,0| 2,1|
+----+----+

This may go on for several pages, but on the final page, there are, for example, 5 datasets to the 2,1 box will be empty. However, I have declared the figure as:

cfig,ax = plt.subplots(3,2)

So in the space for subplot 2,1 there is a default set of axes with ticks and labels. How can I programatically render that space blank and devoid of axes?

— mishaF
quelle

141

You could always hide the axes which you do not need. For example, the following code turns off the 6th axes completely:

import matplotlib.pyplot as plt

hf, ha = plt.subplots(3,2)
ha[-1, -1].axis('off')

plt.show()

and results in the following figure:

An image of a 3x2 grid of graphs, with no graph rendered in the bottom right cell

Alternatively, see the accepted answer to the question Hiding axis text in matplotlib plots for a way of keeping the axes but hiding all the axes decorations (e.g. the tick marks and labels).

— Chris
quelle

Thanks - that's actually even closer to my original question. I already accepted the other answer and adapted my code to use it, but both approaches are great.

— mishaF

Cool, that's indeed nice as there's less add_subplot() clutter.

— moooeeeep

This is marvependous!

— FaCoffee

This does show no plot and one could say that this is a blank plot. I was looking for a plot which has no data, to explicitly show that there is no data. Any easy modification of this answer, which does that?

— Zelphir Kaltstahl

@Zelphir I'm not sure what you're after: the other five plots are empty graphs with no data, so I'm not sure what extra you're asking for. Also, this is a new question. In the future, please ask this as a new question rather than commenting on a old answer.

— Chris

26

A much improved subplot interface has been added to matplotlib since this question was first asked. Here you can create exactly the subplots you need without hiding the extras. In addition, the subplots can span additional rows or columns.

import pylab as plt

ax1 = plt.subplot2grid((3,2),(0, 0))
ax2 = plt.subplot2grid((3,2),(0, 1))
ax3 = plt.subplot2grid((3,2),(1, 0))
ax4 = plt.subplot2grid((3,2),(1, 1))
ax5 = plt.subplot2grid((3,2),(2, 0))

plt.show()

enter image description here

— Hooked
quelle

Wow - that's a nice improvement. So much simpler! Thanks @Hooked!

— mishaF

@Hooked, that last blank space is perfect for adding a legend. Do you know any way to set the legend there?

— Stefano

@Stefano sure there are ways of doing this -- but this would be best posed as a new question, you can even link this answer in your question (welcome to StackOverflow btw!)

— Hooked

6

It's also possible to hide a subplot using the Axes.set_visible() method.

import matplotlib.pyplot as plt
import pandas as pd

fig = plt.figure()
data = pd.read_csv('sampledata.csv')

for i in range(0,6):
ax = fig.add_subplot(3,2,i+1)
ax.plot(range(1,6), data[i])
if i == 5:
    ax.set_visible(False)

— Nick Hunkins
quelle

Your answer is great for both original Axes and extended GeoAxes!

— Fei Yao

1

Would it be an option to create the subplots when you need them?

import matplotlib
matplotlib.use("pdf")
import matplotlib.pyplot as plt

plt.figure()
plt.gcf().add_subplot(421)
plt.fill([0,0,1,1],[0,1,1,0])
plt.gcf().add_subplot(422)
plt.fill([0,0,1,1],[0,1,1,0])
plt.gcf().add_subplot(423)
plt.fill([0,0,1,1],[0,1,1,0])
plt.suptitle("Figure Title")
plt.gcf().subplots_adjust(hspace=0.5,wspace=0.5)
plt.savefig("outfig")

— moooeeeep
quelle

I don't think so because there are other formatting things I need to do that I didn't include in the original question for brevity. One of these is plt.subplots_adjust(wspace=0,hspace=0). I'm not sure that would work after the fact.

— mishaF

@mishaF : you can do subplots_adjust() using this approach. See my edit.

— moooeeeep