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I am not able to specify values ​​for my x-axis , using the matplotlib.pyplot.

In some images the chart.xticks(years) solves the problem , but it seems that when the set of x-axis values ​​is too small , it uses default values like ​​[0,1,2,...,N].

A case that works: Image

A case that does not works: Image

My code:

import matplotlib.pyplot as chart
from matplotlib import lines

   # Settings
    chart.title(file_name)
    chart.xlabel('Years')
    chart.ylabel('Committers/Contributions')
    chart.ylim([0,highest_value + 100])
    chart.xlim(first_year,2017)

    # Values
    committer_line = chart.plot(committers_dict.keys(),committers_dict.values(),'r',label='Committer')
    contribution_line = chart.plot(contributions_dict.keys(),contributions_dict.values(),'b--',label='Contribution')
    years = list(range(first_year,2017))
    chart.xticks(years)

    # Legend
    chart.legend()

    # Show/Save
    chart.savefig(images_path + file_name.replace('.txt','-commiter-contribution.eps'), format='eps')
    chart.show()
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  • Note that it is not reverting to [0,1,2...N] as in the bottom right you can see +2.011e3 meaning it is actually plotting 2011,2012 and so on, so it is just a matter of how you are showing it. Commented Mar 23, 2016 at 18:07

2 Answers 2

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Matplotlib is putting the correct numbers but in scientific notation because there's no more room in the x-axis to put more stuff. That said you can interact directly with the x-axis and state what strings do you want, in what positions, using a value for rotation. The following example (data was randomized):

import matplotlib.pyplot as chart
from matplotlib import lines
import random

title = 'Title'
first_year = 1960
last_year = 2017
x = [year for year in range(first_year,2017)]
y1 = [random.randint(0,10) for year in range(first_year,2017)]
y2 = [random.randint(0,10) for year in range(first_year,2017)]
highest_value = max(y1+y2)

# Settings
chart.title(title)
chart.xlabel('Years')
chart.ylabel('Committers/Contributions')
chart.ylim([0,highest_value + 0.05*highest_value])
chart.xlim(first_year,last_year)

# Values
committer_line = chart.plot(x,y1,'r',label='Committer')
contribution_line = chart.plot(x,y2,'b--',label='Contribution')
years = list(range(first_year,last_year))
years_str = [str(i) for i in range(first_year,last_year)]
chart.xticks(years,years_str,rotation=45)

# Legend
chart.legend()

# Show/Save
#chart.savefig(images_path + file_name.replace('.txt','-commiter-contribution.eps'), format='eps')
chart.show()

, results in:

lots of dates in x axis

, which is a bit cluttered so giving a step to you "Label Code" range:

years = list(range(first_year,last_year,5)) # It's 5!
years_str = [str(i) for i in range(first_year,last_year,5)] # It's 5!

, will ease the x axis information:

a few dates on the x axis

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Comments

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If you look in the lower right hand corner, you'll see that matplotlib simply changed the display of the xtick labels to use scientific notation to save space. To change this you will want to alter the tick label Formatter.

To disable this conversion to scientific notation, you can tweak the default formatter:

ax.get_xaxis().get_major_formatter().set_useOffset(False)

This edits the useOffset parameter of your ScalarFormatter.

If you want to disable this behavior by default, you can edit the axes.formatter.useoffset rcparam.

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