Complete Trigonometric Polynomial Approximation. FFT s Coefficients Evaluation. Fourier Series Expansion calculation. Fixed & manual increment uation interval.Complete & custom graphical output. Only setup the input function, uation interval and code do the rest (minimal title graph change only, however, could be automated with sprintf function). -Complete Trigonometric Polynomial Approximation. FFT s Coefficients Evaluation. Fourier Series Expansion calculation. Fixed & manual increment　uation interval.Complete & custom graphical output. Only setup the input function,　uation interval and code do the rest (minimal title graph change only, however, could be automated with sprintf function).