C++17 STL Cookbook

How to do it...

In this section, we are going to implement the Fourier transformation and its backward transformation and then play around with it to transform some signals:

1. First, we include all the headers and declare that we use the std namespace:

      #include <iostream>      #include <complex>      #include <vector>      #include <algorithm>      #include <iterator>      #include <numeric>      #include <valarray>      #include <cmath>            using namespace std;

2. A data point of a signal is a complex number and shall be represented by std::complex, specialized on the double type. This way, the type alias cmplx stands for two coupled double values, which represent the real and the imaginary parts of a complex number. A whole signal is a vector of such items, which we alias to ...