reducing number of plot ticks

Question

I have too many ticks on my graph and they are running into each other   How can I reduce the number of ticks     For example  I have ticks   1E-6  1E-5  1E-4      1E6  1E7   And I only want   1E-5  1E-3      1E5  1E7   I ve tried playing with the LogLocator  but I haven t been able to figure this out

User · Answer

When a log scale is used the number of major ticks can be fixed with the following command

import matplotlib.pyplot as plt

....

plt.locator_params(numticks=12)
plt.show()

The value set to numticks determines the number of axis ticks to be displayed.

Credits to @bgamari's post for introducing the locator_params() function, but the nticks parameter throws an error when a log scale is used.

User · Answer

Alternatively  if you want to simply set the number of ticks while allowing matplotlib to position them  currently only with MaxNLocator   there is pyplot locator params   pyplot locator params nbins 4    You can specify specific axis in this method as mentioned below  default is both     To specify the number of ticks on both or any single axes pyplot locator params axis  y   nbins 6  pyplot locator params axis  x   nbins 10

User · Answer

If you need one tick every N 3 ticks    N   3    1 tick every 3 xticks pos  xticks labels   plt xticks      get all axis ticks myticks    i for i j in enumerate xticks pos  if not i N     index of selected ticks   obviously you can adjust the offset with  i offset  N   Note that you can get uneven ticks if you wish  e g  myticks    1  3  8   Then you can use plt gca   set xticks myticks     set new X axis ticks  or if you want to replace labels as well plt xticks myticks  newlabels     set new X axis ticks and labels  Beware that axis limits must be set after the axis ticks  Finally  you may wish to draw only a given set of ticks    mylabels     03 2018    09 2019    10 2020   plt draw      needed to populate xticks with actual labels xticks pos  xticks labels   plt xticks      get all axis ticks myticks    i for i j in enumerate b  if j get text   in mylabels  plt xticks myticks  mylabels    assuming mylabels is ordered    if it is not  then sort myticks and reorder it

User · Answer

in case somebody still needs it  and since nothing  here really worked for me  i came up with a very  simple way that keeps the appearance of the  generated plot  as is  while fixing the number  of ticks to exactly N   import numpy as np import matplotlib pyplot as plt  f  ax   plt subplots   ax plot range 100    ymin  ymax   ax get ylim   ax set yticks np round np linspace ymin  ymax  N   2

User · Answer

There s a set ticks   function for axis objects

User · Answer

If somebody still gets this page in search results   fig  ax   plt subplots    plt plot       every nth   4 for n  label in enumerate ax xaxis get ticklabels         if n   every nth    0          label set visible False

User · Answer

The solution  raphael gave is straightforward and quite helpful   Still  the displayed tick labels will not be values sampled from the original distribution but from the indexes of the array returned by np linspace ymin  ymax  N    To display N values evenly spaced from your original tick labels  use the set yticklabels   method  Here is a snippet for the y axis  with integer labels   import numpy as np import matplotlib pyplot as plt  ax   plt gca    ymin  ymax   ax get ylim   custom ticks   np linspace ymin  ymax  N  dtype int  ax set yticks custom ticks  ax set yticklabels custom ticks

User · Answer

To solve the issue of customisation and appearance of the ticks  see the Tick Locators guide on the matplotlib website  ax xaxis set major locator plt MaxNLocator 3    Would set the total number of ticks in the x-axis to 3  and evenly distribute it across the axis   There is also a nice tutorial about this

[python] reducing number of plot ticks

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