Date ticks and rotation in matplotlib

Question

I am having an issue trying to get my date ticks rotated in matplotlib  A small sample program is below  If I try to rotate the ticks at the end  the ticks do not get rotated  If I try to rotate the ticks as shown under the comment  crashes   then matplot lib crashes    This only happens if the x-values are dates  If I replaces the variable dates with the variable t in the call to avail plot  the xticks rotation 70  call works just fine inside avail plot    Any ideas    import numpy as np import matplotlib pyplot as plt import datetime as dt  def avail plot ax  x  y  label  lcolor       ax plot x y  b       ax set ylabel label  rotation  horizontal   color lcolor      ax get yaxis   set ticks           crashes      plt xticks rotation 70       ax2   ax twinx       ax2 plot x   1 for a in y    b       ax2 get yaxis   set ticks         ax2 set ylabel  testing    f  axs   plt subplots 2  sharex True  sharey True  t   np arange 0 01  5  1  s1   np exp t  start   dt datetime now   dates    for val in t      next val   start   dt timedelta 0 val      dates append next val      start   next val  avail plot axs 0   dates  s1   testing    green   avail plot axs 1   dates  s1   testing2    red   plt subplots adjust hspace 0  bottom 0 3  plt yticks  0 5             doesn t crash  but does not rotate the xticks  plt xticks rotation 70  plt show

User · Accepted Answer

If you prefer a non-object-oriented approach, move plt.xticks(rotation=70) to right before the two avail_plot calls, eg

plt.xticks(rotation=70)
avail_plot(axs[0], dates, s1, 'testing', 'green')
avail_plot(axs[1], dates, s1, 'testing2', 'red')

This sets the rotation property before setting up the labels. Since you have two axes here, plt.xticks gets confused after you've made the two plots. At the point when plt.xticks doesn't do anything, plt.gca() does not give you the axes you want to modify, and so plt.xticks, which acts on the current axes, is not going to work.

For an object-oriented approach not using plt.xticks, you can use

plt.setp( axs[1].xaxis.get_majorticklabels(), rotation=70 )

after the two avail_plot calls. This sets the rotation on the correct axes specifically.

User · Answer

Simply use  ax set xticklabels label list  rotation 45

User · Answer

An easy solution which avoids looping over the ticklabes is to just use  fig autofmt xdate    This command automatically rotates the xaxis labels and adjusts their position  The default values are a rotation angle 30   and horizontal alignment  right   But they can be changed in the function call  fig autofmt xdate bottom 0 2  rotation 30  ha  right     The additional bottom argument is equivalent to setting plt subplots adjust bottom bottom   which allows to set the bottom axes padding to a larger value to host the rotated ticklabels   So basically here you have all the settings you need to have a nice date axis in a single command   A good example can be found on the matplotlib page

User · Answer

Another way to applyhorizontalalignment and rotation to each tick label is doing a for loop over the tick labels you want to change   import numpy as np import matplotlib pyplot as plt import datetime as dt  now   dt datetime now   hours    now   dt timedelta minutes x  for x in range 0 24 60 10   days    now   dt timedelta days x  for x in np arange 0 30 1 4    hours value   np random random len hours   days value   np random random len days    fig  axs   plt subplots 2  fig subplots adjust hspace 0 75  axs 0  plot hours hours value  axs 1  plot days days value   for label in axs 0  get xmajorticklabels     axs 1  get xmajorticklabels        label set rotation 30      label set horizontalalignment  right       And here is an example if you want to control the location of major and minor ticks   import numpy as np import matplotlib pyplot as plt import datetime as dt  fig  axs   plt subplots 2  fig subplots adjust hspace 0 75  now   dt datetime now   hours    now   dt timedelta minutes x  for x in range 0 24 60 10   days    now   dt timedelta days x  for x in np arange 0 30 1 4     axs 0  plot hours np random random len hours    x major lct   mpl dates AutoDateLocator minticks 2 maxticks 10  interval multiples True  x minor lct   matplotlib dates HourLocator byhour   range 0 25 1   x fmt   matplotlib dates AutoDateFormatter x major lct  axs 0  xaxis set major locator x major lct  axs 0  xaxis set minor locator x minor lct  axs 0  xaxis set major formatter x fmt  axs 0  set xlabel  minor ticks set to every hour  major ticks start with 00 00    axs 1  plot days np random random len days    x major lct   mpl dates AutoDateLocator minticks 2 maxticks 10  interval multiples True  x minor lct   matplotlib dates DayLocator bymonthday   range 0 32 1   x fmt   matplotlib dates AutoDateFormatter x major lct  axs 1  xaxis set major locator x major lct  axs 1  xaxis set minor locator x minor lct  axs 1  xaxis set major formatter x fmt  axs 1  set xlabel  minor ticks set to every day  major ticks show first day of month   for label in axs 0  get xmajorticklabels     axs 1  get xmajorticklabels        label set rotation 30      label set horizontalalignment  right

User · Answer

Solution works for matplotlib 2 1   There exists an axes method tick params that can change tick properties  It also exists as an axis method as set tick params  ax tick params axis  x   rotation 45    Or   ax xaxis set tick params rotation 45    As a side note  the current solution mixes the stateful interface  using pyplot  with the object-oriented interface by using the command plt xticks rotation 70   Since the code in the question uses the object-oriented approach  it s best to stick to that approach throughout  The solution does give a good explicit solution with plt setp  axs 1  xaxis get majorticklabels    rotation 70

[python] Date ticks and rotation in matplotlib

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