Signature Description Parameters

template<typename ... Ts>
StdDataFrame<std::string>
describe();
        
This function returns a DataFrame indexed by std::string that provides a few statistics about the columns of the calling DataFrame.
The statistics are:
  • Number of items in the column
  • Number of items missing in the column
  • Mean of the items
  • Standard deviation of the items
  • Minimum item in the column
  • Maximum item in the column
  • 25% quantile item in the column
  • 50% quantile item in the column
  • 75% quantile item in the column
Ts: List all the types of all data columns. A type should be specified in the list only once.
static void test_describe()  {

    std::cout << "\nTesting describe( ) ..." << std::endl;

    typedef StdDataFrame<std::string> StrDataFrame;

    StrDataFrame    df;

    try  {
        df.read("data/SHORT_IBM.csv", io_format::csv2);

        auto    desc = df.describe<double, long>();

        desc.write<std::ostream, double>(std::cout, io_format::csv2);
    }
    catch (const DataFrameError &ex)  {
        std::cout << ex.what() << std::endl;
    }
}
C++ DataFrame