Matplotlib.axes.Axes.plot_date() in Python (original) (raw)

Last Updated : 13 Apr, 2020

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.

matplotlib.axes.Axes.plot_date() Function

The Axes.plot_date() function in axes module of matplotlib library is used to plot data that contains dates.

Syntax: Axes.plot_date(self, x, y, fmt=’o’, tz=None, xdate=True, ydate=False, *, 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.
• tz: This parameter is the time zone to use in labeling dates.It contain timezone string.
• xdate: This parameter is also an optional parameter. And it contain boolean values with default value True. If True, the x-axis will be interpreted as Matplotlib dates.
• ydate: This parameter is also an optional parameter. And it contain boolean values with default value True. If True, the y-axis will be interpreted as Matplotlib dates.

Returns: This returns the following:

• **lines:**This returns the list of Line2D objects representing the plotted data.

Below examples illustrate the matplotlib.axes.Axes.plot_date() function in matplotlib.axes:

Example-1:

import datetime

import matplotlib.pyplot as plt

from matplotlib.dates import drange

import numpy as np

date1 = datetime.datetime( 2020 , 4 , 2 )

date2 = datetime.datetime( 2020 , 4 , 6 )

delta = datetime.timedelta(hours = 24 )

dates = drange(date1, date2, delta)

y = np.arange( len (dates))

fig, ax = plt.subplots()

ax.plot_date(dates, y * * 2 )

ax.set_title( 'matplotlib.axes.Axes.plot_date Example1' )

plt.show()

Output:

Example-2:

import datetime

import matplotlib.pyplot as plt

from matplotlib.dates import DayLocator, HourLocator, DateFormatter, drange

import numpy as np

date1 = datetime.datetime( 2020 , 4 , 2 )

date2 = datetime.datetime( 2020 , 4 , 6 )

delta = datetime.timedelta(hours = 6 )

dates = drange(date1, date2, delta)

y = np.arange( len (dates))

fig, ax = plt.subplots()

ax.plot_date(dates, y * * 2 )

ax.set_xlim(dates[ 0 ], dates[ - 1 ])

ax.xaxis.set_major_locator(DayLocator())

ax.xaxis.set_minor_locator(HourLocator( range ( 0 , 25 , 6 )))

ax.xaxis.set_major_formatter(DateFormatter( '%Y-%m-%d' ))

ax.fmt_xdata = DateFormatter( '%Y-%m-%d %H:%M:%S' )

fig.autofmt_xdate()

ax.set_title( 'matplotlib.axes.Axes.plot_date Example2' )

plt.show()

Output: