Marco/dev — Add 'image_slice_offset' as an arg to 'project'

[bommaritom]

These changes include the previously discussed changes to cone3D.py, as well as two other minor changes I've made in passing. Namely I added comments to a "test" file I had created in the past, and I added some text to some .rst (read-the-docs) files.

• cone3D.py: Add image_slice_offset=0.0 to project arguments. Add corresponding functionality on lines 641-642.
• test_forward_proj.py: Add explanatory comments and print statements, add comments to code body.
• clean_install.rst, theory.rst: Add explanation of dev_scripts; copy-paste MBIR theory explanation from svmbir.

Tested: demo_3D_shepp_logan.py, demo_mace3D_fast.py, install_docs.sh

[dyang37]

Tested both the shepp Logan demo and readthedocs. Everything works fine. @cabouman Can we merge this in ASAP?

[cabouman]

Marco, did you test the functionality of the new image_slice_offset argument in order to make sure it functions properly?

[bommaritom]

Hi Prof. Bouman, I have a demo file that runs a forward projection both without image_slice_offset set, with a positive value for image_slice_offset, and with a negative value for image_slice_offset. This demo file behaves as expected. I can add this demo file to the pull request if necessary.

[cabouman]

That's OK. I ran some test scripts, and it ran fine. I just wanted to make sure that you had tested the new feature.