How to: Numerical Derivative in Python

Learn how to take a simple numerical derivative of data using a difference formula in Python.
Script and resources to download can be found at: www.hageslab.c...
Here we use "Spyder" IDE as the Python Shell and the following libraries: numpy and matplotlib
Here is the script:
import numpy as np
import matplotlib.pyplot as plt
def func(x,A,B):
return A*x**2+B*x
xlist = np.linspace(0,10,100)
ylist = func(xlist,2,1.4)
plt.figure(1,dpi=120)
plt.plot(xlist,ylist,label="Function")
def D(xlist,ylist):
yprime = np.diff(ylist)/np.diff(xlist)
xprime=[]
for i in range(len(yprime)):
xtemp = (xlist[i+1]+xlist[i])/2
xprime = np.append(xprime,xtemp)
return xprime, yprime
xprime, yprime = D(xlist,ylist)
plt.plot(xprime,yprime,label="Derivative")
xprime2, yprime2 = D(xprime,yprime)
plt.plot(xprime2,yprime2,label="2nd Derivative")
plt.legend()

[@adilmajeed8439]

Awesome, it would be really cool if you can show the same with the help and paper and then use the numerical computation around it. Looking forward for these kind of videos on regular basis... Appreciate all your efforts

[@dhammapaal]

Simple but outstanding. Deep gratitude! Thank you.

[@sandrofilho7798]

perfect video, thanks!

[@joaocarlosbredadossantos9720]

Awesome explanation mate ! great work !

[@brendanhall6644]

Brilliant video, very well explained! Thanks for posting :)

[@juanagustingonzalez9148]

Great man, but i want something. Im trying to make a code with a table of the function f and its derivative valuated but i dont know how to print without any error

[@RoronoaZoro-td9jj]

With this method, that is np.diff(y) / np.diff(x) will compute the gradient of the data points but the derivative will have one less data point, what can be done about that?

[@blewblew3555]

How to inputs a polynomial in standard algebraic notation and outputs
the first derivative of that polynomial? (python)
If both the inputted polynomial and its derivative
should be represented as strings.