Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute. Example:
Python3
# Implementation of matplotlib function import matplotlib.pyplot as pltimport numpy as np # make an agg figurefig, ax = plt.subplots()ax.plot([1, 2, 3])ax.set_title('matplotlib.axes.Axes.plot() example 1')fig.canvas.draw()plt.show() |
Output: 
The Axes.errorbar() function in axes module of matplotlib library is used to plot y versus x as lines and/or markers with attached errorbars.
Syntax: Axes.errorbar(self, x, y, yerr=None, xerr=None, fmt=”, ecolor=None, elinewidth=None, capsize=None, barsabove=False, lolims=False, uplims=False, xlolims=False, xuplims=False, errorevery=1, capthick=None, *, data=None, **kwargs)
Parameters: This method accept the following parameters that are described below:
- x, y: These parameter are the horizontal and vertical coordinates of the data points.
- fmt: This parameter is an optional parameter and it contains the string value.
- xerr, yerr: These parameter contains an array.And the error array should have positive values.
- ecolor: This parameter is an optional parameter. And it is the color of the errorbar lines with default value NONE.
- elinewidth: This parameter is also an optional parameter. And it is the linewidth of the errorbar lines with default value NONE.
- capsize: This parameter is also an optional parameter. And it is the length of the error bar caps in points with default value NONE.
- barsabove: This parameter is also an optional parameter. It contains boolean value True for plotting errorbars above the plot symbols.Its default value is False.
- lolims, uplims, xlolims, xuplims: These parameter are also an optional parameter. They contain boolean values which is used to indicate that a value gives only upper/lower limits.
- errorevery: This parameter is also an optional parameter. They contain integer values which is used to draws error bars on a subset of the data.
Returns: This returns the container and it is comprises of the following:
- plotline:This returns the Line2D instance of x, y plot markers and/or line.
- caplines:This returns the tuple of Line2D instances of the error bar caps.
- barlinecols:This returns the tuple of LineCollection with the horizontal and vertical error ranges.
Below examples illustrate the matplotlib.axes.Axes.errorbar() function in matplotlib.axes: Example #1:
Python3
# Implementation of matplotlib function import numpy as npimport matplotlib.pyplot as plt# example dataxval = np.arange(0.1, 4, 0.5)yval = np.exp(-xval)fig, ax = plt.subplots()ax.errorbar(xval, yval, xerr = 0.4, yerr = 0.5)plt.show() |
Output: 
Example #2:
Python3
# Implementation of matplotlib function import numpy as npimport matplotlib.pyplot as pltfig = plt.figure()x = np.arange(10)y = 3 * np.sin(x / 20 * np.pi)yerr = np.linspace(0.05, 0.2, 10)plt.errorbar(x, y + 7, yerr = yerr, label ='Line1')plt.errorbar(x, y + 5, yerr = yerr, uplims = True, label ='Line2')plt.errorbar(x, y + 3, yerr = yerr, uplims = True, lolims = True, label ='Line3')upperlimits = [True, False] * 5lowerlimits = [False, True] * 5plt.errorbar(x, y, yerr = yerr, uplims = upperlimits, lolims = lowerlimits, label ='Line4')plt.legend(loc ='upper left')plt.show() |
Output: 
