fseval.m

来自「信号实验常用的simulink模型和mfile,可直接在matlan下运行。」· M 代码 · 共 22 行

function y=fseval(kn,t,wo)
%FSEVAL	Fourier Series Function Evaluation.
%	FSEVAL(Kn,t,Wo) computes values of a real valued function given
%	its complex exponential Fourier series coefficients Kn, at the
%	points given in t where the fundamental frequency is Wo rad/s.
%	Kn contains the Fourier coefficients ascending order:
%	Kn=[ k    k     ... k  ... k     k  ]
%	      -N   -N+1      0      N-1   N
%	if Wo is not given, Wo=1 is assumed.
%	Note: this function creates a matrix of size:
%	rows=length(t) and column=(length(Kn)-1)/2
if nargin==2,wo=1;end
nk=length(kn);
if rem(nk-1,2)|(nk==1)
	error('Number of elements in Kn must be odd and greater than 1.')
end
n=0.5*(nk-1);			% highest harmonic
nwo=wo*(1:n);			% harmonic frequencies
ko=kn(n+1);			% average value
kn=kn(n+2:nk).';		% positive frequency coefs
y=ko+2*(real(exp(j*t(:)*nwo)*kn))';