Book Image

C++17 STL Cookbook

By : Jacek Galowicz
Book Image

C++17 STL Cookbook

By: Jacek Galowicz

Overview of this book

C++ has come a long way and is in use in every area of the industry. Fast, efficient, and flexible, it is used to solve many problems. The upcoming version of C++ will see programmers change the way they code. If you want to grasp the practical usefulness of the C++17 STL in order to write smarter, fully portable code, then this book is for you. Beginning with new language features, this book will help you understand the language’s mechanics and library features, and offers insight into how they work. Unlike other books, ours takes an implementation-specific, problem-solution approach that will help you quickly overcome hurdles. You will learn the core STL concepts, such as containers, algorithms, utility classes, lambda expressions, iterators, and more, while working on practical real-world recipes. These recipes will help you get the most from the STL and show you how to program in a better way. By the end of the book, you will be up to date with the latest C++17 features and save time and effort while solving tasks elegantly using the STL.
Table of Contents (18 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Calculating the error sum of two vectors


There are different possibilities to calculate the numerical error between a target value and an actual value. Measuring the difference between signals consisting of many data points usually involves loops and subtraction of corresponding data points, and so on.

One simple formula to calculate this error between a signal a and a signal b is the following:

For every i, it calculates a[i] - b[i], squares that difference (this way, negative and positive differences become comparable), and, finally, sums those values up. This is again a situation where one could use a loop, but for fun reasons, we will do it with an STL algorithm. The good thing is that we get data-structure independence for free this way. Our algorithm will work on vectors and on list-like data structures, where no direct indexing is possible.

How to do it...

In this section, we are going to create two signals and calculate their error sum:

  1. As always, the include statements come first. Then...