The list's child array (representing the inner values) can be accessed with ListArray::values
https://github.com/apache/arrow/blob/master/cpp/src/arrow/array/array_nested.h#L54 So cast that to a ListArray On Tue, Jul 28, 2020 at 10:38 AM Marc Allen <[email protected]> wrote: > > I'm trying to write a C++ unit test that accesses a populated arrow::Table, > where the table contains a column with a 2-D matrix, i.e. each row has a > list(list(double)). I haven't been able to figure out how to access that data > to finish this unit test. I am getting stuck here: > > auto cmat = table->GetColumnByName("mat"); > auto lmat = std::static_pointer_cast<arrow::ListArray>(cmat->chunk(0)) > // How do I get from the parent ListArray to the child ListArrays? > > I took a look at > https://arrow.apache.org/docs/cpp/examples/row_columnar_conversion.html, but > couldn't quite map it to my use case. Thanks, > > -Marc
