I am using the "knife-edge" technique to find the intensity profile of a rectangular laser beam. The data that is obtained using this method is power, the integral of intensity. Therefore, to get the intensity profile we must differentiate the data.
So, as expected, my data looks like a ramp...
I have the following program that moves a wave on a string with fixed ends. The program solves the wave equation given a initial condition wave. The initial condition is a triangle wave splitting into two pulses.
Here is the code written in Python:
from numpy import *
from matplotlib.pyplot...
I am trying to estimate the second derivative of ##sin(x)## at ##0.4## for ##h=10^{-k}, \ \ k=1, 2, ..., 20## using:
$$\frac{f(x+h)-2f(x)+f(x-h)}{h^2}, \ \ (1)$$
I know the exact value has to be ##f''(0.4)=-sin(0.4)= -0.389418342308651.##
I also want to plot the error as a function ##h## in...