Book Image

Scientific Computing with Python 3

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

Scientific Computing with Python 3

By: Claus Führer, Jan Erik Solem, Olivier Verdier

Overview of this book

Python can be used for more than just general-purpose programming. It is a free, open source language and environment that has tremendous potential for use within the domain of scientific computing. This book presents Python in tight connection with mathematical applications and demonstrates how to use various concepts in Python for computing purposes, including examples with the latest version of Python 3. Python is an effective tool to use when coupling scientific computing and mathematics and this book will teach you how to use it for linear algebra, arrays, plotting, iterating, functions, polynomials, and much more.
Table of Contents (23 chapters)
Scientific Computing with Python 3
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Acknowledgement
Preface
References

Functions acting on arrays


There are different types of functions acting on arrays. Some act elementwise, and they return an array of the same shape. Those are called universal functions. Other array functions return an array of a different shape.

Universal functions

Universal functions are functions that act elementwise on arrays. They thus have an output array that has the same shape as the input array. These functions allow us to compute the result of a scalar function on a whole array at once.

Built-in universal functions

A typical example is the cos function (the one provided by NumPy):

cos(pi) # -1
cos(array([[0, pi/2, pi]])) # array([[1, 0, -1]])

Note that universal functions work on arrays in a componentwise manner. This is also true for operators, such as multiplication or exponent:

2 * array([2, 4]) # array([4, 8])
array([1, 2]) * array([1, 8]) # array([1, 16])
array([1, 2])**2 # array([1, 4])
2**array([1, 2]) # array([1, 4])
array([1, 2])**array([1, 2]) # array...