I have the following simple code to create a data frame.
function writeAmbsFile(fin::String, ambs::Vector{Amb})
df = DataFrame( (index = a.index, stationIndex = a.stationIndex, intClass = a.intClass, class=a.class) for a in ambs)
CSV.write(fin, df)
end
It works earlier, but gave an error message, saying ArgumentError: unable to construct DataFrame from Base.Generator{Array{Amb,1}}