Matplotlib.dates.epoch2num() in Python

Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack.

matplotlib.dates.epoch2num()

The matplotlib.dates.epoch2num() function is used to convert an epoch or a sequence of epochs to a new date format from the day since 0001.

Syntax: matplotlib.dates.epoch2num(e)

Parameters:

e: It can be an epoch or a sequence of epochs.

Returns: A new date format since day 0001.

Example 1:

import random 
import matplotlib.pyplot as plt 
import matplotlib.dates as mdates 
  
# generate some random data 
# for approx 5 yrs 
random_data = [float(random.randint(1487517521, 
                                    14213254713)) 
               for _ in range(1000)] 
  
# convert the epoch format to 
# matplotlib date format  
mpl_data = mdates.epoch2num(random_data) 
  
# plotting the graph 
fig, axes = plt.subplots(1, 1) 
axes.hist(mpl_data, bins = 51, color ='green') 
locator = mdates.AutoDateLocator() 
  
axes.xaxis.set_major_locator(locator) 
axes.xaxis.set_major_formatter(mdates.AutoDateFormatter(locator)) 
  
plt.show() 

Output:

Example 2:

from tkinter import *
from tkinter import ttk 
import time  
import matplotlib 
import queue 
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2Tk 
from matplotlib.figure import Figure 
import matplotlib.animation as animation 
import matplotlib.dates as mdate 
  
  
root = Tk() 
  
graphXData = queue.Queue() 
graphYData = queue.Queue() 
  
def animate(objData): 
      
    line.set_data(list(graphXData.queue),  
                  list(graphYData.queue)) 
      
    axes.relim() 
    axes.autoscale_view() 
  
figure = Figure(figsize =(5, 5), dpi = 100) 
axes = figure.add_subplot(111) 
axes.xaxis_date() 
  
line, = axes.plot([], []) 
axes.xaxis.set_major_formatter(mdate.DateFormatter('%H:%M')) 
  
canvas = FigureCanvasTkAgg(figure, root) 
canvas.get_tk_widget().pack(side = BOTTOM,  
                            fill = BOTH,  
                            expand = True) 
  
for cnt in range (600): 
      
    graphXData.put(matplotlib.dates.epoch2num(time.time()-(600-cnt))) 
    graphYData.put(0) 
  
ani = animation.FuncAnimation(figure, animate, interval = 1000) 
  
root.mainloop() 

Output:

My Personal Notes

matplotlib.dates.epoch2num()

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