function [y,iflaw] = fmconst(N,fnorm,t0);%FMCONST Signal with constant frequency modulation.%	[Y,IFLAW] = FMCONST(N,FNORM,T0) generates a frequency modulation  %	with a constant frequency fnorm.%	The phase of this modulation is such that y(t0)=1.% %	N     : number of points.%	FNORM : normalised frequency.       (default: 0.25)%	T0    : time center.                (default: round(N/2))%	Y     : signal.%	IFLAW : instantaneous frequency law (optional).%%	Example: %	 z=amgauss(128,50,30).*fmconst(128,0.05,50); plot(real(z));%%	See also FMLIN, FMSIN, FMODANY, FMHYP, FMPAR, FMPOWER.%	F. Auger, July 1995.%	Copyright (c) 1996 by CNRS (France).%%	------------------- CONFIDENTIAL PROGRAM -------------------- %	This program can not be used without the authorization of its%	author(s). For any comment or bug report, please send e-mail to %			    lemoine@alto.unice.fr if (nargin == 0), error ( 'The number of parameters must be at least 1.' );elseif (nargin == 1), t0=round(N/2); fnorm=0.25 ;elseif (nargin ==2), t0=round(N/2); % this has been changed from N/2 to round N/2 for matlab 5end;if (N<=0), error('N must be greater or equal to 1.');elseif (abs(fnorm)>0.5), error('The normalised frequency must be between -0.5 and 0.5');else tmt0=(1:N)'-t0; y = exp(j*2.0*pi*fnorm*tmt0); y=y/y(t0); if (nargout==2), iflaw=fnorm*ones(N,1); end;end;