5. Vector operations III#
In addition to applying operations on vectors, we can apply functions to them. Let’s see how this works.
Summary of commands#
In this exercise, we will demonstrate the following:
NumPy functions such as exponentials (
np.exp()
) and sine (np.sin()
).NumPy constants such as \(\pi\).
Applying functions#
Evaluate the function \(y\) given below between \(x = 0\) and \(x = \pi\).
\[ y = e^{x} \sin (2x) + \dfrac{x^2}{3} \]
To do so, first create a vector \(\vec{x}\) containing equally spaced elements in the domain of the function. Then compute the corresponding vector \(\vec{y}\). Each element of \(\vec{y}\) will be equal to the value of the function evaluated at the corresponding elements of \(\vec{x}\).
import numpy as np
x = np.linspace(0, np.pi) # default is 50 elements, you may want more sometimes
y = np.exp(x) * np.sin(2*x) + x ** 2 / 3
y
array([ 0. , 0.13771464, 0.29383853, 0.46718755, 0.65609852,
0.85839999, 1.07139032, 1.29182422, 1.51590945, 1.73931503,
1.95719228, 2.1642102 , 2.35460615, 2.52225297, 2.66074322,
2.76349114, 2.82385236, 2.83526142, 2.79138623, 2.68629865,
2.5146595 , 2.27191606, 1.95450931, 1.56008778, 1.08772428,
0.538131 , -0.08613175, -0.78045877, -1.53802098, -2.34961072,
-3.20351786, -4.0854438 , -4.97846034, -5.8630205 , -6.71702818,
-7.51597311, -8.23313709, -8.83987689, -9.30598788, -9.60015163,
-9.69046916, -9.54507982, -9.13286404, -8.42422589, -7.39194955,
-6.01212063, -4.26510143, -2.13654593, 0.38156221, 3.28986813])