% creates a waveform to test the LLRF history buffer
% Checked equivalent with Octave-2.0.14 and Matlab-7.0beta, 2003-Mar-19
envelope=[zeros(20,1); [0:.005:1]'; 1+zeros(3164,1); [1:-.005:0]'; zeros(510,1)];
l=length(envelope);
t=[1:l]'*.025;  % microseconds
f=10.005;       % MHz
w=2*pi*f;
z0=.002+.99i;

wave=envelope.*sin(w*t);
fa=[1 (z0+conj(z0)) (z0*conj(z0))];  % poles
fb=[1 0 -1];  % zeros
zi=[1 i -1]';
fs=abs((fa*zi)/(fb*zi));
% Crude pseudo-random number.
% Should reproduce across all versions of Matlab and Octave.
rn=((rem([17:17:17*l]',29)+rem([39:39:39*l]',53)+rem([53:53:53*l]',71))-75)/27;
wave2=fs*filter(fb, fa, wave)+rn*.002;

% Output format is suitable for Verilog $readmemh()
file=fopen('given.dat','w');
for n=[1:l]
   fprintf(file,'0x%x\n',floor(wave2(n)*1700+2058));
end
fclose(file);