Book Image

Scientific Computing with Python - Second Edition

By : Claus Führer, Jan Erik Solem, Olivier Verdier
Book Image

Scientific Computing with Python - Second Edition

By: Claus Führer, Jan Erik Solem, Olivier Verdier

Overview of this book

Python has tremendous potential within the scientific computing domain. This updated edition of Scientific Computing with Python features new chapters on graphical user interfaces, efficient data processing, and parallel computing to help you perform mathematical and scientific computing efficiently using Python. This book will help you to explore new Python syntax features and create different models using scientific computing principles. The book presents Python alongside mathematical applications and demonstrates how to apply Python concepts in computing with the help of examples involving Python 3.8. You'll use pandas for basic data analysis to understand the modern needs of scientific computing, and cover data module improvements and built-in features. You'll also explore numerical computation modules such as NumPy and SciPy, which enable fast access to highly efficient numerical algorithms. By learning to use the plotting module Matplotlib, you will be able to represent your computational results in talks and publications. A special chapter is devoted to SymPy, a tool for bridging symbolic and numerical computations. By the end of this Python book, you'll have gained a solid understanding of task automation and how to implement and test mathematical algorithms within the realm of scientific computing.
Table of Contents (23 chapters)
20
About Packt
22
References

4.9.2 Solving a least square problem with SVD

A linear equation system , with  being an  matrix and , is called an overdetermined linear system. In general, it has no classical solution and you seek a vector  with the property:

Here,  denotes the Euclidean vector norm .

This problem is called a least square problem. A stable method to solve it is based on factorizing , with  being an  orthogonal matrix,  an  orthogonal matrix, and  an matrix with the property  for all . This factorization is called a singular value decomposition (SVD).

We write

with a diagonal matrix . If we assume that  has full rank, then  is invertible and it can be shown that 

holds. 

If we split with being an  submatrix, then the preceding equation can be simplified to:

 

SciPy provides a function called svd, which we use to solve this task:

import scipy.linalg...