Determining the Fourier series coefficients
We have seen that determining the Fourier series coefficients by directly attempting to determine the amplitude of individual frequency components can be difficult, even when the individual frequency components are known. Usually, however, they are not known. A general formula for computing the coefficients is given by
The discrete-time case is somewhat simpler.
Its practical importance in computing is much greater. Since this sum is finite, the DFS coefficients can be easily computed precisely on a computer.