matplotlib: histogram and bin labels

dimka picture dimka · Apr 11, 2013 · Viewed 16.5k times · Source

I'm trying to plot a histogram with bar chart, and I'm having difficulties figuring out how to align the x-axis labels with the actual bins. The code below generates the following plot: Bar chart

as you can see, the end of each x-label is not aligned to the center of its bin. The way i'm thinking about this is: when i apply a 45-degree rotation, the label pivots around its geometrical center. I was wondering if it's possible to move the pivot up to the top of the label. (Or simply translate all the labels slightly left.)

import matplotlib.pyplot as plt
import numpy as np

#data
np.random.seed(42)
data = np.random.rand(5)
names = ['A:GBC_1233','C:WERT_423','A:LYD_342','B:SFS_23','D:KDE_2342']

ax = plt.subplot(111)
width=0.3
bins = map(lambda x: x-width/2,range(1,len(data)+1))
ax.bar(bins,data,width=width)
ax.set_xticks(map(lambda x: x, range(1,len(data)+1)))
ax.set_xticklabels(names,rotation=45)

plt.show()

Answer

HYRY picture HYRY · Apr 11, 2013

Use:

ax.set_xticklabels(names,rotation=45, rotation_mode="anchor", ha="right")

The output is:

enter image description here