How can I set the aspect ratio in matplotlib

Question

I m trying to make a square plot  using imshow   i e  aspect ratio of 1 1  but I can t  None of these work   import matplotlib pyplot as plt  ax   fig add subplot 111 aspect  equal   ax   fig add subplot 111 aspect 1 0  ax set aspect  equal   plt axes   set aspect  equal     It seems like the calls are just being ignored  a problem I often seem to have with matplotlib

User · Answer

After many years of success with the answers above, I have found this not to work again - but I did find a working solution for subplots at

https://jdhao.github.io/2017/06/03/change-aspect-ratio-in-mpl

With full credit of course to the author above (who can perhaps rather post here), the relevant lines are:

ratio = 1.0
xleft, xright = ax.get_xlim()
ybottom, ytop = ax.get_ylim()
ax.set_aspect(abs((xright-xleft)/(ybottom-ytop))*ratio)

The link also has a crystal clear explanation of the different coordinate systems used by matplotlib.

Thanks for all great answers received - especially @Yann's which will remain the winner.

User · Answer

What is the matplotlib version you are running  I have recently had to upgrade to 1 1 0  and with it  add subplot 111 aspect  equal   works for me

User · Answer

you should try with figaspect  It works for me  From the docs      Create a figure with specified aspect ratio   If arg is a number  use that aspect ratio     If arg is an array  figaspect will   determine the width and height for a figure that would fit array   preserving aspect ratio   The figure width  height in inches are   returned   Be sure to create an axes with equal with and height  eg      Example usage        make a figure twice as tall as it is wide   w  h   figaspect 2     fig   Figure figsize  w h     ax   fig add axes  0 1  0 1  0 8  0 8     ax imshow A    kwargs       make a figure with the proper aspect for an array   A   rand 5 3    w  h   figaspect A    fig   Figure figsize  w h     ax   fig add axes  0 1  0 1  0 8  0 8     ax imshow A    kwargs    Edit  I am not sure of what you are looking for  The above code changes the canvas  the plot size   If you want to change the size of the matplotlib window  of the figure  then use    In  68   f   figure figsize  5 1     this does produce a window of 5x1  wxh

User · Answer

Third times the charm  My guess is that this is a bug and Zhenya s answer suggests it s fixed in the latest version  I have version 0 99 1 1 and I ve created the following solution    import matplotlib pyplot as plt import numpy as np  def forceAspect ax aspect 1       im   ax get images       extent    im 0  get extent       ax set aspect abs  extent 1 -extent 0    extent 3 -extent 2    aspect   data   np random rand 10 20   fig   plt figure   ax   fig add subplot 111  ax imshow data  ax set xlabel  xlabel   ax set aspect 2  fig savefig  equal png   ax set aspect  auto   fig savefig  auto png   forceAspect ax aspect 1  fig savefig  force png     This is  force png     Below are my unsuccessful  yet hopefully informative attempts    Second Answer   My  original answer  below is overkill  as it does something similar to axes set aspect    I think you want to use axes set aspect  auto    I don t understand why this is the case  but it produces a square image plot for me  for example this script   import matplotlib pyplot as plt import numpy as np  data   np random rand 10 20   fig   plt figure   ax   fig add subplot 111  ax imshow data  ax set aspect  equal   fig savefig  equal png   ax set aspect  auto   fig savefig  auto png     Produces an image plot with  equal  aspect ratio   and one with  auto  aspect ratio    The code provided below in the  original answer  provides a starting off point for an explicitly controlled aspect ratio  but it seems to be ignored once an imshow is called    Original Answer   Here s an example of a routine that will adjust the subplot parameters so that you get the desired aspect ratio   import matplotlib pyplot as plt  def adjustFigAspect fig aspect 1               Adjust the subplot parameters so that the figure has the correct     aspect ratio              xsize ysize   fig get size inches       minsize   min xsize ysize      xlim    4 minsize xsize     ylim    4 minsize ysize     if aspect  lt  1          xlim    aspect     else          ylim    aspect     fig subplots adjust left  5-xlim                          right  5 xlim                          bottom  5-ylim                          top  5 ylim   fig   plt figure   adjustFigAspect fig aspect  5  ax   fig add subplot 111  ax plot range 10  range 10    fig savefig  axAspect png     This produces a figure like so    I can imagine if your having multiple subplots within the figure  you would want to include the number of y and x subplots as keyword parameters  defaulting to 1 each  to the routine provided  Then using those numbers and the hspace and wspace keywords  you can make all the subplots have the correct aspect ratio

User · Answer

A simple option using plt gca   to get current axes and set aspect         plt gca   set aspect  equal    in place of your last line

User · Answer

This answer is based on  Yann s answer   It will set the aspect ratio for linear or log-log plots   I ve used additional information from https   stackoverflow com a 16290035 2966723 to test if the axes are log-scale   def forceAspect ax aspect 1        aspect is width height     scale str   ax get yaxis   get scale       xmin xmax   ax get xlim       ymin ymax   ax get ylim       if scale str   linear           asp   abs  xmax-xmin   ymax-ymin   aspect     elif scale str   log           asp   abs  scipy log xmax -scipy log xmin    scipy log ymax -scipy log ymin    aspect     ax set aspect asp    Obviously you can use any version of log you want  I ve used scipy  but numpy or math should be fine

[python] How can I set the aspect ratio in matplotlib?

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