Book Image

IPython Interactive Computing and Visualization Cookbook - Second Edition

By : Cyrille Rossant
Book Image

IPython Interactive Computing and Visualization Cookbook - Second Edition

By: Cyrille Rossant

Overview of this book

Python is one of the leading open source platforms for data science and numerical computing. IPython and the associated Jupyter Notebook offer efficient interfaces to Python for data analysis and interactive visualization, and they constitute an ideal gateway to the platform. IPython Interactive Computing and Visualization Cookbook, Second Edition contains many ready-to-use, focused recipes for high-performance scientific computing and data analysis, from the latest IPython/Jupyter features to the most advanced tricks, to help you write better and faster code. You will apply these state-of-the-art methods to various real-world examples, illustrating topics in applied mathematics, scientific modeling, and machine learning. The first part of the book covers programming techniques: code quality and reproducibility, code optimization, high-performance computing through just-in-time compilation, parallel computing, and graphics card programming. The second part tackles data science, statistics, machine learning, signal and image processing, dynamical systems, and pure and applied mathematics.
Table of Contents (19 chapters)
IPython Interactive Computing and Visualization CookbookSecond Edition
Contributors
Preface
Index

Finding the root of a mathematical function


In this short recipe, we will see how to use SciPy to find the root of a simple mathematical function of a single real variable.

How to do it...

  1. Let's import NumPy, SciPy, scipy.optimize, and matplotlib:

    >>> import numpy as np
        import scipy as sp
        import scipy.optimize as opt
        import matplotlib.pyplot as plt
        %matplotlib inline
  2. We define the mathematical function in Python. We will try to find a root of this function numerically. Here, a root corresponds to a fixed point of the cosine function:
    >>> def f(x):
            return np.cos(x) - x
  3. Let's plot this function on the interval (using 1000 samples):
    >>> x = np.linspace(-5, 5, 1000)
        y = f(x)
        fig, ax = plt.subplots(1, 1, figsize=(5, 3))
        ax.axhline(0, color='k')
        ax.plot(x, y)
        ax.set_xlim(-5, 5)
  4. We see that this function has a unique root on this interval (this is because the function's sign changes on this interval). The scipy.optimize module...