function drawmainscan(Fmn, cvmn, chrid, chroms, header)
%draw a mainscan figure
%figure
hold on
mp = zeros(size(chroms));
j = 1;
for i = chroms
   plot(find(chrid==i), Fmn(find(chrid==i)));
   mp(j) = mean(find(chrid==i));
   j = j+1;
end
xlabel('Chromosome')
set(gca,'Ticklength',[0 0])
set(gca,'XTick',mp)
set(gca,'XTickLabel',num2str(chroms'))
axis([0 length(chrid)+1 0 max(Fmn)])
pv = [0.1 0.05 0.01];
for i = 2:4
   refline(0, cvmn(i))
   text(70, cvmn(i), num2str(pv(i-1)))
end
title(header)