pro write_tau_cldtopP_histos, fname, tau_bins, cldtopP_bins, tau_cldtopP_histo_total

; check to see if the file exists

OPENR, 1, fname, ERROR = err

if err eq 0 then begin
close, 1

; file exists, read the data
cdfid=ncdf_open(fname,/write)

print, 'writing to ',fname

tau_cldtopP_histo_total_id=ncdf_varid(cdfid, 'tau_cldtopP_histo_total')

ncdf_varput, cdfid, tau_cldtopP_histo_total_id, tau_cldtopP_histo_total

endif else begin	;OPENR, 1, fname, ERROR = err

; file does not exist, create it
cdfid=ncdf_create(fname,/clobber)
print, 'created ',fname
tau_bins_did=ncdf_dimdef(cdfid,'tau_bins',n_elements(tau_bins))
cldtopP_bins_did=ncdf_dimdef(cdfid,'cldtopP_bins',n_elements(cldtopP_bins))

tau_bins_id=ncdf_vardef(cdfid,'tau_bins',$
	[tau_bins_did],/float)
cldtopP_bins_id=ncdf_vardef(cdfid,'cldtopP_bins',$
	[cldtopP_bins_did],/float)
tau_cldtopP_histo_total_id=ncdf_vardef(cdfid,'tau_cldtopP_histo_total',$
	[tau_bins_did,cldtopP_bins_did],/long)


ncdf_control, cdfid, /endef
ncdf_varput, cdfid, tau_bins_id, tau_bins
ncdf_varput, cdfid, cldtopP_bins_id, cldtopP_bins

ncdf_varput, cdfid, tau_cldtopP_histo_total_id, tau_cldtopP_histo_total

endelse		;OPENR, 1, fname, ERROR = err


NCDF_CLOSE, cdfid

return
end