% Routine to generate artificial spectra of binary stars.
%
% Syntax: sp = bgen(x)
%
% X is an input wavelength spectrum.
%
% D. Holmgren, Mar 6 94. holmgren@phobos.astro.uwo.ca
function sp = bgen(x)
% Enter parameters for both components...
a1 = input('Primary depth ');
x1 = input('Primary RV ');
w1 = input('Primary width ');
a2 = input('Secondary depth ');
x2 = input('Secondary RV ');
w2 = input('Secondary width ');
% use random noise to simulate observations...
snr = input('Signal-to-noise ratio ');
nl = length(x);
sp = zeros(nl,1);
rand('normal');
n = rand(nl,1) ./ snr;
% assume gaussian line profiles...
s1 = 2*w1*w1;
s2 = 2*w2*w2;
sp = 1 - ( a1 .* exp(-((x-x1).^2)./s1) + a2 .* exp(-((x-x2).^2)./s2));
sp = sp + n;
plot(x,sp)