function   peak_to_peak = waterfall(x, scale)%WATERF            "Waterfall" Plot%------%   Usage:    waterf(X)%%        plots the waveforms in X(time,rcvr) vs. "time"%        Each trace is auto scaled so that the peak-to-peak value%        is at most 1.0; then each trace is offset by 1 unit.%%        NOTE: a scaling of 13 is applied to bunch the plots together.%%    waterf(x, A) uses a scale factor of A ==> peak-to-peak will be < A.%        ex: wp(x, 11.0) will bunch the wfms even closer together.%%  NOTE: the hidden line method used in this function is only approximate.%        It looks OK when the number of time points is >30; otherwise,%          it is obvious where the mistakes are being made.%---------------------------------------------------------------% copyright 1994, by C.S. Burrus, J.H. McClellan, A.V. Oppenheim,% T.W. Parks, R.W. Schafer, & H.W. Schussler.  For use with the book% "Computer-Based Exercises for Signal Processing Using MATLAB"% (Prentice-Hall, 1994).%---------------------------------------------------------------[N,M] = size(x);offset = min([0.15*N/M;1]);Ttemp = [0:(N-1)]'*ones(1,M);for k = 2:M   Ttemp(:,k) = Ttemp(:,k) + offset*(k-1);endif nargin == 1  scale = 13.0;                % default scalingendpeak_to_peak = max(max(x)-min(x));  % RETURN maximum peak-to-peak valuescale = scale/peak_to_peak;Xtemp(:,1) = scale*x(:,1) + 1;if M > 1  for i=2:M    % hidden line "removal", actually adjusts signal values    ttt = x(:,i)*scale + i;    ttti = [Xtemp(:,i-1) [Xtemp(2:N,i-1); Xtemp(N,i-1)]]*...              [1-offset;offset];    % makes mistakes in deep valleys    Xtemp(:,i) = ttt.*(ttt>=ttti) + ttti.*(ttt<ttti);  endendplot(Ttemp, Xtemp, '-w');       %--- scale wfms