#### Overview of this book

Python, one of the world's most popular programming languages, has a number of powerful packages to help you tackle complex mathematical problems in a simple and efficient way. These core capabilities help programmers pave the way for building exciting applications in various domains, such as machine learning and data science, using knowledge in the computational mathematics domain. The book teaches you how to solve problems faced in a wide variety of mathematical fields, including calculus, probability, statistics and data science, graph theory, optimization, and geometry. You'll start by developing core skills and learning about packages covered in Python’s scientific stack, including NumPy, SciPy, and Matplotlib. As you advance, you'll get to grips with more advanced topics of calculus, probability, and networks (graph theory). After you gain a solid understanding of these topics, you'll discover Python's applications in data science and statistics, forecasting, geometry, and optimization. The final chapters will take you through a collection of miscellaneous problems, including working with specific data formats and accelerating code. By the end of this book, you'll have an arsenal of practical coding solutions that can be used and modified to solve a wide range of practical problems in computational mathematics and data science.
Preface
Basic Packages, Functions, and Concepts
Free Chapter
Mathematical Plotting with Matplotlib
Working with Randomness and Probability
Geometric Problems
Finding Optimal Solutions
Miscellaneous Topics
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# Using discrete Fourier transforms for signal processing

One of the most useful tools coming from calculus is the Fourier transform. Roughly speaking, the Fourier transform changes the representation, in a reversible way, of certain functions. This change of representation is particularly useful in dealing with signals represented as a function of time. In this instance, the Fourier transform takes the signal and represents it as a function of frequency; we might describe this as transforming from signal space to frequency space. This can be used to identify the frequencies present in a signal for identification and other processing. In practice, we will usually have a discrete sample of a signal, so we have to use the discrete Fourier transform to perform this kind of analysis. Fortunately, there is a computationally efficient algorithm, called the fast Fourier transform(FFT), for applying the discrete Fourier transform to a sample.

We will follow a common process for...