pro insert_gaps,data,gapindices,baddata
if n_elements(baddata) eq 0 then baddata=!values.f_nan
data0 = data[0]
data[0] = baddata
ndata = n_elements(data)
nbad = n_elements(gapindices)
if (nbad gt 0) and (gapindices[0] ge 0) then begin
ind = indgen(ndata+nbad)
ind(ndata:*) = gapindices
ind = ind(sort(ind))
u = uniq(ind)
b = replicate(1b,ndata+nbad)
b(u) = 0
w = where(b)
ind[w] = 0
data = data[ind]
data[0] = data0
endif
return
end