Python：如何 plot y=cosh(x) *cos(5x)

Question

using Python I would like to plot a curve for the function y=cosh(x)*cos(5x) in my Jupyter Notebook.

In other words: (cosine hyperbolicus of x) times (cosine of 5x)

How do I do this? What do I need to import? Thank you very much in advance.

Greetings

Answer 1

Specify the range of values for x that you need. You can use Seaborn on top of Matplotlib to make it prettier, but this is optional:

import seaborn as sns

import matplotlib.pyplot as plt

import numpy as np

x = np.arange(-5,5,0.1)   # start,stop,step

y= (np.cosh(x))*(np.cos(5*x) )

# set a grey background (use sns.set_theme() if seaborn version 0.11.0 or above) 
sns.set(style="darkgrid")

plt.plot(x,y)
plt.show()

Answer 2

You will need to import a plotting library and a maths library. The most commonly used plotting library is matplotlib , and for maths it's numpy . For plotting, bokeh is a an alternative to matplotlib , which I think is great because graphs are interactive by default. The disadvantage is that because it's not as widely used as matplotlib , you're less likely to find help on it in terms of StackOverflow answers and tutorials.

Anyway, to the code:

# Import the necessary packages and modules
import matplotlib.pyplot as plt
import numpy as np

# Set your x-range and calculate y
xmin = -2.5
xmax = 2.5
numPoints = 100

x = np.linspace(xmin, xmax, numPoints)
y = np.cosh(x)*np.cos(5*x)

# Plot -- it really can be this simple [1]
plt.plot(x,y)

Both of the graphing libraries above give you flexible options on where to place the axes, legends, titles, and so on. I recommend searching for beginner's tutorials on them to learn this stuff in depth.

[1] There are two ways to plot in matplotlib . What is shown here is the MATLAB-like interface. The other method is to use the object-based interface, which takes a bit more of getting used to, and requires a bit more boilerplate code, but that's what you will end up using once you demand more control over the appearance of your plots.

I recommend starting with the MATLAB-like commands first. The documentation has a good beginner's tutorial: https://matplotlib.org/stable/tutorials/introductory/pyplot.html