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pythonmatplotlibx-axis

Why are bar chart x-axis ticks showing strange and wrong negative values?

Why is my X-axis ticks showing Negative values when the Xaxis values range from 43990 - 44003. 

import matplotlib.pyplot as plt
x=[44000, 44001, 44002, 44003, 43990, 43991, 43992, 43993, 43994, 43995, 43996, 43997, 43998, 43999]
y=[8, 5, 3, 1, 1, 3, 4, 10, 4, 11, 4, 10, 17, 19]
plt.bar(x,y)
plt.show()

I am seeing the following output. I was expecting x-axis to range from 43990 - 44003 why negative x-axis ticks ?

I have tried this on a couple of machines, all showing similar strange behaviour on recent versions of python and matplotlib (tried a few different versions)

Python 3.6.4 |Anaconda, Inc.| (default, Jan 16 2018, 18:10:19) [GCC 7.2.0] on linux

Python 3.4.3 (default, Nov 17 2016, 01:08:31)

Strangely enough many trivial toy example x and y arrays are giving me expected figures.

For e.g the follwowing snippet shows the expected graph with correct x-axis tick labels

x=[20,30,90,70, 50, 60, 80, 70]
y=[3,2,5,10, 3, 9, 7, 6]
plt.bar(x,y)
plt.show()

correct result for above example

What obvious thing am i missing here ?

Solution

  • You need to disable the offset:

    plt.ticklabel_format(useOffset=False)

    Another option would be to input custom tick labels:

    plt.bar(x, y, tick_label=x)