Matplotlib - error bars not centered on points

Question

I know it's been an issue before in matplotlib - but it should have been fixed, right?

When I exec. my example code for a scatter plot:

%matplotlib inline
import matplotlib.pyplot as plt
plt.style.use('seaborn-whitegrid')
import numpy as np


plt.xlabel(r'$Label \, in \, Latex$')
plt.ylabel(r'$Label \, in \, Latex$')
plt.title(r'$Title \, in \, Latex$')
#plt.text(1, 15, r'$Latex \, Example \, Text$')

x=[1, 2, 3, 4]
y=[1, 4, 9, 16]


plt.axis([0, 6, 0, 20])
plt.errorbar(x, y, yerr=1, fmt='.k', capsize=3)
plt.savefig('foo.pdf', bbox_inches="tight")

the error bars are not centered on the points. I am using matplotlib 3.02 - Anaconda somehow doesn't recognize that there's 3.03.

Sheldore · Accepted Answer · 2019-03-12 14:19:27Z

7

I found the following work around: Specifying a linewidth=1 for the error bar makes them centered. I tried several values and anything below 1.5 works centered but anything above 1.5 (inclusive) makes it shift off center. I do not know the reason. It could be related to the dpi

import matplotlib.pyplot as plt
plt.style.use('seaborn-whitegrid')
import numpy as np

plt.xlabel(r'$Label \, in \, Latex$')
plt.ylabel(r'$Label \, in \, Latex$')
plt.title(r'$Title \, in \, Latex$')
#plt.text(1, 15, r'$Latex \, Example \, Text$')

x=[1, 2, 3, 4]
y=[1, 4, 9, 16]

plt.axis([0, 6, 0, 20])
plt.errorbar(x, y, yerr=1, lw=1, fmt='.k', capsize=3)

edited Mar 12, 2019 at 14:19

answered Mar 12, 2019 at 14:08

Sheldore

39.2k9 gold badges63 silver badges76 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Balou · Accepted Answer · 2019-08-07 12:25:38Z

1

Saving as .svg solves the issue for me. Using jupyter notebook the plot is shown with non-centered error bars but it is saved correctly.

import matplotlib.pyplot as plt
plt.style.use('seaborn-whitegrid')
import numpy as np

plt.xlabel(r'$Label \, in \, Latex$')
plt.ylabel(r'$Label \, in \, Latex$')
plt.title(r'$Title \, in \, Latex$')
#plt.text(1, 15, r'$Latex \, Example \, Text$')

x=[1, 2, 3, 4]
y=[1, 4, 9, 16]

plt.axis([0, 6, 0, 20])
plt.errorbar(x, y, yerr=1, lw=2, fmt='o', capsize=3)

plt.savefig('TEST.svg', bbox_inches='tight', format='svg')

answered Aug 7, 2019 at 12:25

Balou

736 bronze badges

Collectives™ on Stack Overflow

Matplotlib - error bars not centered on points

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related