function x = fmsin(N, p, phs)% fmsin -- create a signal with a sinusoidal frequency modulation%%  Usage%    x = fmsin(N, p, phs)%%  Inputs%    N    length of the signal%    p    number of cycles (optional, default is 1)%    phs  phase shift of the instantaneous frequency (optional, default is 0)%%  Outputs%    x    signal% Copyright (C) -- see DiscreteTFDs/Copyrighterror(nargchk(1,3,nargin));if (nargin<3)  phs = 0;endif (nargin<2)  p = 1;endn = (0:N-1)';x = exp(-j*N/4/p*cos(p*2*pi*n/N + phs));