Resize a figure automatically in matplotlib

Question

Is there a way to automatically resize a figure to properly fit contained plots in a matplotlib/pylab image?

I'm creating heatmap (sub)plots that differ in aspect ratio according to the data used.

I realise I could calculate the aspect ratio and manually set it, but surely there's an easier way?

score 74 · Accepted Answer · answered Aug 14 '09 at 15:57

74

Use bbox_inches='tight'

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cm as cm

X = 10*np.random.rand(5,3)

fig = plt.figure(figsize=(15,5),facecolor='w') 
ax = fig.add_subplot(111)
ax.imshow(X, cmap=cm.jet)

plt.savefig("image.png",bbox_inches='tight',dpi=100)

...only works when saving images though, not showing them.

answered Aug 14 '09 at 15:57

pufferfish

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What does that fig.add_subplot(111) indicate? I mean the number within the square brackets ((111)) – dangerous Mar 03 '15 at 06:27
My answer (https://stackoverflow.com/a/10448306/1273751) works for showing and saving – Homero Esmeraldo Jun 20 '19 at 14:54
what does dpi=100 do? – Wara Oct 28 '20 at 14:28
dpi controls the dots per inch. If you are putting the plot on a powerpoint or something, then you would want to increase the dpi for clarity. Alternatively, you could save it with vector graphics. – Progress Dec 20 '22 at 19:32

score 21 · Answer 2 · answered Dec 26 '16 at 15:38

21

Another way of doing this is using the matplotlib tight_layout function

import matplotlib.pyplot as plt
fig,(ax) = plt.subplots(figsize=(8,4), ncols=1)
data = [0,1,2,3,4]
ax.plot(data)
fig.tight_layout()
fig.show()

answered Dec 26 '16 at 15:38

Simon Hobbs

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Homero Esmeraldo · Answer 3 · 2013-07-08T03:49:35.660

18

just use aspect='auto' when you call imshow

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cm as cm

X = 10*np.random.rand(5,3)
plt.imshow(X, aspect='auto')

it works even if it is just for showing and not saving

edited Jul 08 '13 at 03:49

answered May 04 '12 at 11:51

Homero Esmeraldo

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score 5 · Answer 4 · answered Nov 14 '18 at 21:19

you can try using axis('scaled')

import matplotlib.pyplot as plt
import numpy

#some dummy images
img1 = numpy.array([[.1,.2],[.3,.4]]) 
img2 = numpy.array([[.1,.2],[.3,.4]])

fig,ax = plt.subplots()
ax.imshow(img1,extent=[0,1,0,1])
ax.imshow(img2,extent=[2,3,0,1])
ax.axis('scaled') #this line fits your images to screen 
plt.show()

score 4 · Answer 5 · edited May 23 '17 at 12:10

4

Do you mean changing the size of the image or the area that is visable within a plot?

The size of a figure can be set with Figure.set_figsize_inches. Also the SciPy Cookbook has an entry on changing image size which contains a section about multiple images per figure.

Also take a look at this question.

edited May 23 '17 at 12:10

Community

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answered Aug 13 '09 at 10:31

wierob

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I mean the dimensions of the Figure object. i.e. Crop the figure to fit the contained plot(s). One would probably have to provide either a width or a height first, and have the other calculated. – pufferfish Aug 13 '09 at 10:35
I think the correct command is ``.set_size_inches`` without the ``fig`` – innisfree Nov 17 '13 at 22:20

score 2 · Answer 6 · edited Feb 02 '19 at 13:14

2

Also possible to use ax.autoscale with ax object

ax.autoscale(enable=True)

edited Feb 02 '19 at 13:14

Andrew D.

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answered Jan 30 '19 at 02:35

Shakujin

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Hm, `enable=True` is already the default value... – Stefan Sep 16 '21 at 14:29

Resize a figure automatically in matplotlib

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