Book Image

NumPy Cookbook

Book Image

NumPy Cookbook

Overview of this book

Today's world of science and technology is all about speed and flexibility. When it comes to scientific computing, NumPy is on the top of the list. NumPy will give you both speed and high productivity. "NumPy Cookbook" will teach you all about NumPy, a leading scientific computing library. NumPy replaces a lot of the functionality of Matlab and Mathematica, but in contrast to those products, it is free and open source. "Numpy Cookbook" will teach you to write readable, efficient, and fast code that is as close to the language of Mathematics as much as possible with the cutting edge open source NumPy software library. You will learn about installing and using NumPy and related concepts. At the end of the book, we will explore related scientific computing projects. This book will give you a solid foundation in NumPy arrays and universal functions. You will also learn about plotting with Matplotlib and the related SciPy project through examples. "NumPy Cookbook" will help you to be productive with NumPy and write clean and fast code.
Table of Contents (17 chapters)
NumPy Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Repeating audio fragments


As we saw in Chapter 2, we can do neat things with WAV files. It's just a matter of downloading the file and loading it with SciPy. Let's download a WAV file and repeat it three times. We will skip some of the steps that we already saw in Chapter 2.

How to do it...

  1. Repeating the audio fragment.

    Although NumPy has a repeat function, in this case, it is more appropriate to use the tile function. The repeat function would have the effect of enlarging the array by repeating individual elements, and not repeating the contents of it.

    The following IPython session should clarify the difference between these functions:

    In: x = array([1, 2])
    
    In: x
    Out: array([1, 2])
    
    In: repeat(x, 3)
    Out: array([1, 1, 1, 2, 2, 2])
    
    In: tile(x, 3)
    Out: array([1, 2, 1, 2, 1, 2])
    

    Now armed with this knowledge apply the tile function:

    repeated = numpy.tile(data, int(sys.argv[1]))
  2. Plot the audio data.

    We can plot the audio data with Matplotlib:

    matplotlib.pyplot.title("Repeated")
    matplotlib.pyplot...