function [mrv,sig] = rv(w,f)
% Function to compute RV's from spectra interactively.
%
% D. Holmgren holmgren@phobos.astro.uwo.ca

wl = [6331.95 6347.10];
nl = input('Number of lines: ');
for k = 1:nl
 wlo = input('Enter lower lambda limit: ');
 whi = input('Enter upper lambda limit: ');
 plot(w,f)
 axis([wlo whi min(f) max(f)])
 [ix,iy] = ginput(1);
 rv(k) = 300000 * (ix(1) - wl(k))/wl(k);
end
mrv = mean(rv); sig = std(rv)/sqrt(nl);
axis; clg