(Course Code: BMATS201) solutions using Python Programming
Hi everyone! This blog provides solutions for the lab component of the newly introduced subject “Mathematics-II for Computer Science and Engineering stream” (BMATS201) for II semester students of VTU. I have provided solutions for the lab exercises using Python. All the programs shown below have been tested on Python 3.11.7 on Ubuntu 22.04 OS using Anaconda Distribution.
Installation Instructions
A detailed procedure of installing ANACONDA distribution and necessary tools for this is provided in my other blog listed below. https://moodle.sit.ac.in/blog/setting-up-anaconda-python-programming-environment/
Questions
- Program to compute area, surface area, volume and centre of gravity
- Evaluation of improper integrals
- Finding gradient, divergent, curl and their geometrical interpretation
- Basis and Dimension for a vector space and Graphical representation of linear transformation
- Computing the inner product and orthogonality
- Solution of algebraic and transcendental equations by Ramanujan’s, Regula-Falsi and Newton-Raphson method
- Interpolation/Extrapolation using Newton’s forward and backward difference formula
- Computation of area under the curve using Trapezoidal, Simpson’s (1/3)rd and (3/8)th rule
- Solution of ODE of first order and first degree by Taylor’s series and Modified Euler’s method
- Solution of ODE of first order and first degree by Runge-Kutta 4th order and Milne’s predictor-corrector method
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1) Program to compute area, surface area, volume and centre of gravity
Below is a Python program that computes the area, surface area, volume, and center of gravity of a given 3D shape. This example specifically targets a sphere, but you can adapt it for other shapes by defining appropriate functions for area, surface area, volume, and center of gravity calculations.
import math
def sphere_area(radius):
return 4 * math.pi * radius ** 2
def sphere_surface_area(radius):
return 4 * math.pi * radius ** 2
def sphere_volume(radius):
return (4/3) * math.pi * radius ** 3
def sphere_center_of_gravity(radius):
return (3/8) * radius
def main():
radius = float(input("Enter the radius of the sphere: "))
area = sphere_area(radius)
surface_area = sphere_surface_area(radius)
volume = sphere_volume(radius)
center_of_gravity = sphere_center_of_gravity(radius)
print(f"Area of the sphere: {area}")
print(f"Surface area of the sphere: {surface_area}")
print(f"Volume of the sphere: {volume}")
print(f"Center of gravity of the sphere: {center_of_gravity}")
main()
To run this program online click n the link below
Output Sample
Enter the radius of the sphere: 6
Area of the sphere: 452.3893421169302
Surface area of the sphere: 452.3893421169302
Volume of the sphere: 904.7786842338603
Center of gravity of the sphere: 2.25
Additional code
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
def plot_wireframe_sphere(radius):
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
u = np.linspace(0, 2 * np.pi, 100)
v = np.linspace(0, np.pi, 100)
x = radius * np.outer(np.cos(u), np.sin(v))
y = radius * np.outer(np.sin(u), np.sin(v))
z = radius * np.outer(np.ones(np.size(u)), np.cos(v))
ax.plot_wireframe(x, y, z, color='b')
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Z')
ax.set_title('Wireframe Sphere')
plt.show()
def main():
radius = float(input("Enter the radius of the sphere: "))
plot_wireframe_sphere(radius)
main()
Enter the radius of the sphere: 6
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2) Evaluation of improper integrals
Python Code
from scipy import integrate
# Define the function to be integrated
def integrand(x):
return (x**3 + 2*x + 7) /(x + 2)
# Define the limits of integration
a = 0
b = 1
# Evaluate the improper integral with increased limit
result, error = integrate.quad(integrand, a, b)
print(f"Result of the improper integral: {result}")
print(f"Estimated error: {error}")
To run this program online click n the link below
Output
Result of the improper integral: 3.3060077927925113
Estimated error: 3.6704059711484397e-14
3) Finding gradient, divergent, curl and their geometrical interpretation
Python Program
import numpy as np
import sympy as sp
# Define symbols
x, y, z = sp.symbols('x y z')
# Define vector field
F = sp.Matrix([x**2, y**2, z**2])
# Define variables for differentiation
variables = (x, y, z)
# Define gradient
gradient_F = sp.Matrix([sp.diff(F[i], var) for var in variables for i in range(3)]).reshape(3, 3)
# Calculate divergence
divergence_F = sp.diff(F[0], x) + sp.diff(F[1], y) + sp.diff(F[2], z)
# Calculate curl
curl_F = sp.Matrix([sp.diff(F[(i+1) % 3], variables[(i+2) % 3]) - sp.diff(F[(i+2) % 3], variables[(i+1) % 3])
for i in range(3)])
# Print results
print("Vector Field F(x, y, z) = ", F)
print("\nGradient of F:")
print(gradient_F)
print("\nDivergence of F:")
print(divergence_F)
print("\nCurl of F:")
print(curl_F)
# Geometrical interpretations
# Gradient gives the direction of maximum change in the scalar field.
# Divergence represents how much a vector field is spreading out or converging at a point.
# Curl indicates the rotation or "whirl" of the vector field at a point.
To run this program online click n the link below
Output
Vector Field F(x, y, z) = Matrix([[x**2], [y**2], [z**2]])
Gradient of F:
Matrix([[2*x, 0, 0], [0, 2*y, 0], [0, 0, 2*z]])
Divergence of F:
2*x + 2*y + 2*z
Curl of F:
Matrix([[0], [0], [0]])
4)Computation of basis and dimension for a vector space and Graphical representation of linear transformation
Python Code
import numpy as np
import matplotlib.pyplot as plt
def basis_and_dimension(matrix):
# Compute the reduced row echelon form
rref_matrix = np.linalg.matrix_rank(matrix)
dimension = np.linalg.matrix_rank(matrix.T)
return rref_matrix, dimension
def plot_linear_transformation(matrix):
# Create a set of 2D vectors
vectors = np.array([[1, 0], [0, 1]])
# Apply linear transformation to the vectors
transformed_vectors = np.dot(matrix, vectors)
# Plot original and transformed vectors
plt.figure(figsize=(8, 6))
plt.quiver([0, 0], [0, 0], vectors[:,0], vectors[:,1], angles='xy', scale_units='xy', scale=1, color=['r', 'b'], label='Original Vectors')
plt.quiver([0, 0], [0, 0], transformed_vectors[:,0], transformed_vectors[:,1], angles='xy', scale_units='xy', scale=1, color=['g', 'y'], label='Transformed Vectors')
plt.xlabel('x')
plt.ylabel('y')
plt.axhline(0, color='black',linewidth=0.5)
plt.axvline(0, color='black',linewidth=0.5)
plt.grid(color = 'gray', linestyle = '--', linewidth = 0.5)
plt.axis('equal')
plt.legend()
plt.title('Linear Transformation')
plt.show()
# Example matrix representing a linear transformation
A = np.array([[1, 2], [3, 4]])
# Compute basis and dimension
rref, dimension = basis_and_dimension(A)
print("Reduced Row Echelon Form:\n", rref)
print("Dimension of Column Space:", dimension)
# Plot linear transformation
plot_linear_transformation(A)
To run this program online click n the link below
Output
Reduced Row Echelon Form:
2
Dimension of Column Space: 2
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5) Computing the inner product and orthogonality
Python Code
import numpy as np
def inner_product(vector1, vector2):
# Compute the inner product (dot product) between two vectors
return np.dot(vector1, vector2)
def check_orthogonality(vector1, vector2):
# Check if two vectors are orthogonal (their inner product is zero)
return inner_product(vector1, vector2) == 0
# Example vectors
vector1 = np.array([1, 2, 3])
vector2 = np.array([-1, 1, 0])
# Compute the inner product of the vectors
result = inner_product(vector1, vector2)
print("Inner product of vector1 and vector2:", result)
# Check orthogonality
if check_orthogonality(vector1, vector2):
print("Vectors vector1 and vector2 are orthogonal.")
else:
print("Vectors vector1 and vector2 are not orthogonal.")
# Example vectors
vector3 = np.array([1, 2, 3])
vector4 = np.array([-1, 1, 2])
# Compute the inner product of the vectors
result = inner_product(vector3, vector4)
print("Inner product of vector3 and vector4:", result)
# Check orthogonality
if check_orthogonality(vector3, vector4):
print("Vectors vector3 and vector4 are orthogonal.")
else:
print("Vectors vector3 and vector4 are not orthogonal.")
To run this program online click n the link below
Output
Inner product of vector1 and vector2: 1
Vectors vector1 and vector2 are not orthogonal.
Inner product of vector3 and vector4: 7
Vectors vector3 and vector4 are not orthogonal.
6) Solution of algebraic and transcendental equations by Ramanujan’s, Regula-Falsi and Newton-Raphson method
Python Code
import numpy as np
def ramanujan(f, a, b, tol=1e-6, max_iter=100):
# Ramanujan's method for solving equations
for _ in range(max_iter):
c = (a * f(b) - b * f(a)) / (f(b) - f(a))
if np.abs(f(c)) < tol:
return c
if f(a) * f(c) < 0:
b = c
else:
a = c
raise ValueError("Ramanujan's method did not converge")
def regula_falsi(f, a, b, tol=1e-6, max_iter=100):
# Regula-Falsi method for solving equations
for _ in range(max_iter):
c = (a * f(b) - b * f(a)) / (f(b) - f(a))
if np.abs(f(c)) < tol:
return c
if f(a) * f(c) < 0:
b = c
else:
a = c
raise ValueError("Regula-Falsi method did not converge")
def newton_raphson(f, f_prime, x0, tol=1e-6, max_iter=100):
# Newton-Raphson method for solving equations
x = x0
for _ in range(max_iter):
x_new = x - f(x) / f_prime(x)
if np.abs(f(x_new)) < tol:
return x_new
x = x_new
raise ValueError("Newton-Raphson method did not converge")
# Example usage:
# Define the function
def f(x):
return x**3 - 2*x - 5
# Define the derivative of the function
def f_prime(x):
return 3*x**2 - 2
# Initial guesses
x0_ramanujan = 1
x0_regula_falsi = 1
x0_newton_raphson = 1
# Solve using Ramanujan's method
solution_ramanujan = ramanujan(f, 1, 3)
print("Solution using Ramanujan's method:", solution_ramanujan)
# Solve using Regula-Falsi method
solution_regula_falsi = regula_falsi(f, 1, 3)
print("Solution using Regula-Falsi method:", solution_regula_falsi)
# Solve using Newton-Raphson method
solution_newton_raphson = newton_raphson(f, f_prime, 1)
print("Solution using Newton-Raphson method:", solution_newton_raphson)
To run this program online click n the link below
Output
Solution using Ramanujan's method: 2.094551400063298
Solution using Regula-Falsi method: 2.094551400063298
Solution using Newton-Raphson method: 2.0945514815642077
7) Interpolation/Extrapolation using Newton’s forward and backward difference formula
Python Program
import numpy as np
import matplotlib.pyplot as plt
def forward_difference_coefficients(y):
n = len(y)
coeffs = np.zeros((n, n))
coeffs[:, 0] = y
for j in range(1, n):
for i in range(n - j):
coeffs[i, j] = coeffs[i+1, j-1] - coeffs[i, j-1]
return coeffs
def backward_difference_coefficients(y):
n = len(y)
coeffs = np.zeros((n, n))
coeffs[:, 0] = y
for j in range(1, n):
for i in range(j, n):
coeffs[i, j] = coeffs[i, j-1] - coeffs[i-1, j-1]
return coeffs
def newton_interpolation(x, y, coeffs, xi):
n = len(x)
h = x[1] - x[0]
fxi = coeffs[0, 0]
for j in range(1, n):
term = coeffs[0, j]
for i in range(j):
term *= (xi - x[i]) / ((j+1) * h)
fxi += term
return fxi
# Data points
x = np.array([0, 1, 2, 3, 4])
y = np.array([1, 2, 4, 8, 16])
# Coefficients for forward and backward difference formula
coeffs_forward = forward_difference_coefficients(y)
coeffs_backward = backward_difference_coefficients(y)
# Visualization of coefficients
plt.figure(figsize=(12, 6))
# Forward Difference Coefficients
plt.subplot(1, 2, 1)
plt.imshow(coeffs_forward, cmap='coolwarm', aspect='auto')
plt.title('Forward Difference Coefficients')
plt.xlabel('Order of Difference')
plt.ylabel('Data Points')
plt.colorbar(label='Coefficient Value')
# Backward Difference Coefficients
plt.subplot(1, 2, 2)
plt.imshow(coeffs_backward, cmap='coolwarm', aspect='auto')
plt.title('Backward Difference Coefficients')
plt.xlabel('Order of Difference')
plt.ylabel('Data Points')
plt.colorbar(label='Coefficient Value')
plt.tight_layout()
plt.show()
# Interpolation
xi = 2.5
forward_interpolation = newton_interpolation(x, y, coeffs_forward, xi)
backward_interpolation = newton_interpolation(x, y, coeffs_backward, xi)
print("Interpolated value at xi using forward difference formula:", forward_interpolation)
print("Interpolated value at xi using backward difference formula:", backward_interpolation)
To run this program online click n the link below
Output
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8) Computation of area under the curve using Trapezoidal, Simpson’s (1/3)rd and (3/8)th rule
Python Code
import numpy as np
import matplotlib.pyplot as plt
def trapezoidal_rule(f, a, b, n):
h = (b - a) / n
x = np.linspace(a, b, n+1)
y = f(x)
area = h * (np.sum(y) - 0.5 * (y[0] + y[-1]))
return area, x, y
def simpsons_one_third_rule(f, a, b, n):
h = (b - a) / n
x = np.linspace(a, b, n+1)
y = f(x)
area = h/3 * (y[0] + 4*np.sum(y[1:-1:2]) + 2*np.sum(y[2:-2:2]) + y[-1])
return area, x, y
def simpsons_three_eighth_rule(f, a, b, n):
h = (b - a) / n
x = np.linspace(a, b, n+1)
y = f(x)
area = 3*h/8 * (y[0] + 3*np.sum(y[1:-1:3]) + 3*np.sum(y[2:-2:3]) + 2*np.sum(y[3:-3:3]) + y[-1])
return area, x, y
# Example function
def f(x):
return np.sin(x)
# Integration interval
a = 0
b = np.pi
# Number of subintervals
n = 10
# Compute area using different rules
area_trapezoidal, x_trap, y_trap = trapezoidal_rule(f, a, b, n)
area_simpsons_one_third, x_simp13, y_simp13 = simpsons_one_third_rule(f, a, b, n)
area_simpsons_three_eighth, x_simp38, y_simp38 = simpsons_three_eighth_rule(f, a, b, n)
# Plot the function
x = np.linspace(a, b, 100)
y = f(x)
plt.figure(figsize=(10, 6))
plt.plot(x, y, label='Function: sin(x)')
plt.fill_between(x_trap, 0, y_trap, alpha=0.3, label='Trapezoidal Rule Area')
plt.fill_between(x_simp13, 0, y_simp13, alpha=0.3, label="Simpson's 1/3 Rule Area")
plt.fill_between(x_simp38, 0, y_simp38, alpha=0.3, label="Simpson's 3/8 Rule Area")
plt.xlabel('x')
plt.ylabel('y')
plt.title('Area Under the Curve Approximation')
plt.legend()
plt.grid(True)
plt.show()
# Print results
print("Area under the curve using Trapezoidal rule:", area_trapezoidal)
print("Area under the curve using Simpson's 1/3 rule:", area_simpsons_one_third)
print("Area under the curve using Simpson's 3/8 rule:", area_simpsons_three_eighth)
To run this program online click n the link below
Output
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9) Solution of ODE of first order and first degree by Taylor’s series and Modified Euler’s method
Python Code
import numpy as np
import matplotlib.pyplot as plt
def taylors_series(f, y0, t0, tn, h):
t_values = np.arange(t0, tn+h, h)
y_values = np.zeros_like(t_values)
y_values[0] = y0
for i in range(1, len(t_values)):
t = t_values[i-1]
y = y_values[i-1]
y_prime = f(t, y)
y_double_prime = f(t, y_prime)
y_values[i] = y + h*y_prime + (h**2 / 2)*y_double_prime
return t_values, y_values
def modified_euler(f, y0, t0, tn, h):
t_values = np.arange(t0, tn+h, h)
y_values = np.zeros_like(t_values)
y_values[0] = y0
for i in range(1, len(t_values)):
t = t_values[i-1]
y = y_values[i-1]
y_prime = f(t, y)
y_modified = y + h*y_prime
y_prime_modified = f(t+h, y_modified)
y_values[i] = y + (h/2)*(y_prime + y_prime_modified)
return t_values, y_values
# Example ODE: y' = y - t^2 + 1, y(0) = 0.5
def f(t, y):
return y - t**2 + 1
# Initial conditions
y0 = 0.5
t0 = 0
tn = 2
h = 0.2
# Solve using Taylor's series method
t_values_taylor, y_values_taylor = taylors_series(f, y0, t0, tn, h)
# Solve using Modified Euler's method
t_values_euler, y_values_euler = modified_euler(f, y0, t0, tn, h)
# Plot the solutions
plt.figure(figsize=(10, 6))
plt.plot(t_values_taylor, y_values_taylor, label="Taylor's Series")
plt.plot(t_values_euler, y_values_euler, label="Modified Euler's Method")
plt.xlabel('t')
plt.ylabel('y')
plt.title('Solution of ODE: y\' = y - t^2 + 1')
plt.legend()
plt.grid(True)
plt.show()
To run this program online click n the link below
Output
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10) Solution of ODE of first order and first degree by Runge-Kutta 4th order and Milne’s predictor-corrector method
Python Code
import numpy as np
import matplotlib.pyplot as plt
def runge_kutta_4th_order(f, y0, t0, tn, h):
t_values = np.arange(t0, tn+h, h)
y_values = np.zeros_like(t_values)
y_values[0] = y0
for i in range(1, len(t_values)):
t = t_values[i-1]
y = y_values[i-1]
k1 = h * f(t, y)
k2 = h * f(t + h/2, y + k1/2)
k3 = h * f(t + h/2, y + k2/2)
k4 = h * f(t + h, y + k3)
y_values[i] = y + (k1 + 2*k2 + 2*k3 + k4) / 6
return t_values, y_values
def milnes_predictor_corrector(f, y0, t0, tn, h):
t_values = np.arange(t0, tn+h, h)
y_values = np.zeros_like(t_values)
y_values[0] = y0
for i in range(1, 4):
t = t_values[i-1]
y = y_values[i-1]
k1 = h * f(t, y)
k2 = h * f(t + h/2, y + k1/2)
k3 = h * f(t + h/2, y + k2/2)
k4 = h * f(t + h, y + k3)
y_values[i] = y + (k1 + 2*k2 + 2*k3 + k4) / 6
for i in range(3, len(t_values)):
t_n3 = t_values[i-3]
t_n2 = t_values[i-2]
t_n1 = t_values[i-1]
y_n3 = y_values[i-3]
y_n2 = y_values[i-2]
y_n1 = y_values[i-1]
t = t_values[i-1]
y_p = y_n1 + 4*h/3 * (2*f(t, y_n1) - f(t_n1, y_n2) + 2*f(t_n2, y_n3))
t = t_values[i]
y_values[i] = y_n1 + h/3 * (f(t, y_p) + 4*f(t_n1, y_n1) + f(t_n2, y_n2))
return t_values, y_values
# Example ODE: y' = y - t^2 + 1, y(0) = 0.5
def f(t, y):
return y - t**2 + 1
# Initial conditions
y0 = 0.5
t0 = 0
tn = 2
h = 0.2
# Solve using Runge-Kutta 4th order method
t_values_rk4, y_values_rk4 = runge_kutta_4th_order(f, y0, t0, tn, h)
# Solve using Milne's predictor-corrector method
t_values_milne, y_values_milne = milnes_predictor_corrector(f, y0, t0, tn, h)
# Plot the solutions
plt.figure(figsize=(10, 6))
plt.plot(t_values_rk4, y_values_rk4, label="Runge-Kutta 4th Order")
plt.plot(t_values_milne, y_values_milne, label="Milne's Predictor-Corrector")
plt.xlabel('t')
plt.ylabel('y')
plt.title('Solution of ODE: y\' = y - t^2 + 1')
plt.legend()
plt.grid(True)
plt.show()
To run this program online click n the link below
Output
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