uproot | ROOT I/O in pure Python and NumPy | Data Visualization library

Directories (uproot.ReadOnlyDirectory) and TTrees (uproot.TTree) are objects that can initiate more reading, so they are navigable as Mappings with keys() and square-bracket syntax (__getitem__).

This object evidently has class type TVectorT_3c_double_3e_ (a Python model, uproot.Model, of C++ class TVectorT). Some objects like this have custom "behaviors," which are user-friendly properties and methods. For example, the model of TParameter has a value property (see uproot.behaviors.TParameter). This one does not.

When Uproot reads an object and does not have custom behaviors, you can still access its C++ private member data through the uproot.Model.member method or the uproot.Model.all_members property (dict). In fact, these are how high-level behaviors get implemented: the reading of C++ private member data is automatic, but humans have to design high-level APIs by writing functions to access them in a more user-friendly way, something that's happened for TParameter but not TVectorT yet.

(To first order, ROOT has infinitely many classes.)

So, to be explicit, do

IIUC:

Input data:

Perhaps this is too short to be an answer, but

1. Upgrade to Awkward 1.x (you can still import awkward0 and use ak.from_awkward0 and ak.to_awkward0 to go back and forth in the same process).
2. Create an array of single-item lists, perhaps in NumPy (ak.from_numpy), perhaps by slicing a one-dimensional array with np.newaxis.
3. Concatenate it with your other array using ak.concatenate with axis=1. The first dimension needs to be the same (len of both arrays must be equal), but the second dimensions are unconstrained.

To give you something to start with, you can use fancyhdr and tikz to design your own header:

You're not doing something wrong: it's a NotImplementedError because memberwise serialization has not been implemented in Uproot. That's Issue #38, which has been getting a lot of attention recently.

Other people finding this question, years later: check to see if Issue #38 has been resolved.

TMatrixT is a class that Uproot doesn't have any specialized code for (yet?), but it can be read anyway because its "streamers" (instructions for deserialization) are included in the ROOT file. It's therefore presented in a rather generic way.

You can find all of an object's member data in all_members (dict) or extract only one using the member("memberName") method. So, for instance, try

This is actually a question about Uproot. In this line:

There’s a module in upROOT called “vector” which works for these purposes; it’s new in uproot4 (running with awkward1.0). Anyone interested can check it out here. I’m marking this as solved since this is exactly what I'm looking for, though it should be noted that "vector" is currently in development so it's not yet complete.

Thanks!

This will be better documented when it's ported to Uproot 4, but the best documentation we have on writing jagged arrays in Uproot 3 right now is the pull request and associated issues (all linked to each other):

https://github.com/scikit-hep/uproot3/pull/477

Here is an example from the tests: