function [a,b,ao]=fsform(c,d,co)%FSFORM Fourier Series Format Conversion.% Kn=FSFORM(An,Bn,Ao) converts the trigonometric FS with% An being the COSINE and Bn being the SINE coefficients to% the complex exponential FS with coefficients Kn.% Ao is the DC component and An, Bn and Ao are assumed to be real.%% [Kn,i]=FSFORM(An,Bn,Ao) returns the index vector i that% identifies the harmonic number of each element of Kn.%% [An,Bn,Ao]=FSFORM(Kn) does the reverse format conversion.% D.C. Hanselman, University of Maine, Orono, ME 04469% 1/12/95% Copyright (c) 1996 by Prentice-Hall, Inc. nc=length(c);if nargin==1		% complex exp --> trig form if rem(nc-1,2)|(nc==1)  error('Number of elements in K must be odd and greater than 1') end nn=(nc+3)/2; a=2*real(c(nn:nc)); b=-2*imag(c(nn:nc)); ao=real(c(nn-1));elseif nargin==3	% trig form --> complex exp form nd=length(d); if nc~=nd,  error('A and B must be the same length') end a=0.5*(c-sqrt(-1)*d); a=[conj(a(nc:-1:1)) co(1) a]; b=-nc:nc;else error('Improper number of input arguments.')end