pro fakemarsflats2,fn
;  quick procedure to make fake mars flats to fool pipe with 
;  8 blacks and 8 skys.
openr,lun1,fn,/get_lun
dum = lonarr(256,256,16)
readu,lun1,dum
dum = swap_endian(dum)
black = total(dum[*,*,0:7],3)/8.
sky = total(dum[*,*,8:15],3)/8.
shiny = black*.15
free_lun,lun1
close,lun1

openw,lun1,fn,/get_lun
dum2 = lonarr(256,256,4)
dum2[*,*,0]=black
dum2[*,*,1]=sky
dum2[*,*,2]=shiny
dum2[*,*,3]=sky

writeu,lun1,swap_endian(dum2)
free_lun,lun1
close,lun1

print,'make sure you change the header file'
end