Working with rows and columns of a ntuple

Hi,

Thanks for your replies. I have answered about reading the SQLite file in the other thread.

Using TCsvDS is indeed very nice to convert the csv into a data frame. And TDataFrame’s functional and lazy approach is very elegant.

So

 auto fileName = "../data/input_samples.csv";
 auto tdf = ROOT::Experimental::TDF::MakeCsvDataFrame(fileName);
 auto filteredEvents = tdf.Filter("code == 211").Count();
 std::cout << "Count = " << *filteredEvents << '\n';

works with my data.

However, I have the feeling that I can only work using columns (which is nice for histograms and correlations between variables). But I still don’t see how to easily extract a subset of the variables for a row (a slice of the time series for a site, like v1_t1, v1_t2, …, v1_tn in my table above) in order to plot it or perfom a polynomial fitting.

Is there an example of how to do this?

Thanks.

Garjola