interpolation and Fourier expansions for computing with periodic functions. Many algorithms related to trigonometric interpolation are readily available in Chebfun; several examples are available here. References Kendall E. Atkinson, An Introduction to Numerical Analysis (2nd edition), Section 3.8. John Wiley & Sons, New York, 1988. . M. T. Heideman, D. H. Johnson, and C. S. Burrus, "Gauss and the history of the fast Fourier transform," IEEE ASSP Magazine 1 (4), 14–21 (1984). G.B. Wright, M. Javed, H. Montanelli, and L.N. Trefethen, "Extension of Chebfun to periodic functions," SIAM. J. Sci. Comput., 37 (2015), C554-C573 A. Zygmund, Trigonometric Series, Volume II, Chapter X, Cambridge University Press, 1988. External links www.chebfun.org Interpolation Trigonometry Articles with example MATLAB/Octave code