question about documentation

Is there a more pedagogical presentation of variables & computes than is available
in the LAMMPS documentation? I have studied that documentation and have trouble
understanding it.

For example, I’m trying to read into a python array (using PyLammps) the pe/atom
for each atom. In doing so I realize that I do not understand well enough how different
kinds of variables & computes work in LAMMPS.

Thank you.

Murray Daw

Is there a more pedagogical presentation of variables & computes than is available
in the LAMMPS documentation? I have studied that documentation and have trouble
understanding it.

For example, I’m trying to read into a python array (using PyLammps) the pe/atom
for each atom. In doing so I realize that I do not understand well enough how different
kinds of variables & computes work in LAMMPS.

That is really difficult to answer. Tn part you are asking for a rather general and introductory documentation, but then again, you are describing that you are doing programming which will require less knowledge about how to “use” LAMMPS features, but rather how they are implemented and how to program them. For that you are better off checking out the source code and reading the comments in it as well. Using python interface is putting an additional twist on that, since this is based on the library interface. the library interface is an abstraction on the C++ based functionality of the actual implementation. Again, a lot of the details of that is in the source code as comments.

Writing a tutorial kind of introduction in these matters is quite a tall order, and thus i am not aware of anything that is not already in the manual or in the PDFs and presentations posted on the LAMMPS website.

With all that in mind, it is probably better you describe what you understood so far and where you are struggling and what exactly you are looking to do. I already gave you some specific advice on exactly the issues you are referring to for the case in your previous post, so I am now wondering what else are you missing to achieve what you want to do.

Axel.

Hi Murray - did you also read this section of the LAMMPS manual:
https://lammps.sandia.gov/doc/Howto_output.html

If it does not seem sufficient, what info do you think is missing?
We could add to it.

Note that the Python part of your Q is a separate issue,
which has more to do with the library interface to LAMMPS and
converting a C ptr to a Python numpy array.

Steve