function write_mean, rday, day_a4000d1, day_a4000d2, day_a4000c2, day_a4000s2, day_p4000d1, day_p4000d2, day_p4000c2, day_p4000s2

;------------------------tagesmittel
;-----------format: rday, mean(array), stddev(array), ... 
daily_mean='/data/etnas1/ulysses/ket/rate/shifttab/daily_mean.dat'
openw, 4, daily_mean, /append, width=400

if (n_elements(day_a4000d1) gt 1 and n_elements(day_a4000d2) gt 1 and n_elements(day_a4000c2) gt 1  and n_elements(day_a4000s2) gt 1 and n_elements(day_p4000d1) gt 1 and n_elements(day_p4000d2) gt 1 and n_elements(day_p4000c2) gt 1  and n_elements(day_p4000s2) gt 1) then begin
  
printf, 4, rday, mean(day_a4000d1[1:*]), stddev(day_a4000d1[1:*]), mean(day_a4000d2[1:*]), stddev(day_a4000d2[1:*]), mean(day_a4000c2[1:*]), stddev(day_a4000c2[1:*]), mean(day_a4000s2[1:*]), stddev(day_a4000s2[1:*]), mean(day_p4000d1[1:*]), stddev(day_p4000d1[1:*]), mean(day_p4000d2[1:*]), stddev(day_p4000d2[1:*]), mean(day_p4000c2[1:*]), stddev(day_p4000c2[1:*]), mean(day_p4000s2[1:*]), stddev(day_p4000s2[1:*])

endif
close, 4
free_lun, 4

end