Time for action – solving a linear system

Solve an example of a linear system with the following steps:

1. Create A and b:

   A = np.mat("1 -2 1;0 2 -8;-4 5 9")
   print("A\n", A)
   b = np.array([0, 8, -9])
   print("b\n", b)

   A and b appear as follows:

   
2. Solve this linear system with the solve() function:

   x = np.linalg.solve(A, b)
   print("Solution", x)

   The solution of the linear system is as follows:

   Solution [ 29.  16.   3.]
   

3. Check whether the solution is correct with the dot() function:

   print("Check\n", np.dot(A , x))

   The result is as expected:

   Check
   [[ 0.  8. -9.]]
   

What just happened?

We solved a linear system using the solve() function from the NumPy linalg module and checked the solution with the dot() function. Please refer to the solution.py file in this book's code bundle:

from __future__ import print_function
import numpy as np

A = np.mat("1 -2 1;0 2 -8;-4 5 9")
print("A\n", A)

b = np.array([0, 8, -9])
print("b\n&quot...