dampsin.m

这是一个 York大学开发的FDTD代码。很好用的工具

function v = dampsin(t,wn,z)
%Generate Damped sine wave
%dampsin (t,wn,z)
%  t = time
% wn = Natural frequency
%  z = damping factor

    kzm=(z-sqrt(z.^2-1)).*wn; kzp=(z+sqrt(z.^2-1)).*wn;
    
% this gives unit dc component but doesn't like zero or unit z
    v=((wn./(2*sqrt(z.^2-1)))'*ones(1,size(t,2))).*(exp(-kzm'*t) - exp(-kzp'*t));

% this gives unit amplitude spectral component sine wave
%  
    v=((abs(sqrt(z.^2-1))*2.*z.*wn./(2*sqrt(z.^2-1)))'*ones(1,size(t,2))).*(exp(-kzm'*t) - exp(-kzp'*t));


  %v=((abs(sqrt(z.^2-1))./(2*sqrt(z.^2-1)))'*ones(1,size(t,2))).*(exp(-kzm'*t) - exp(-kzp'*t));

end