Refactor - Metric & Utils

[JeS24]

Fixes #113, #141, #410, #507, #508, #514 , #515.
Notes on fixes:

1. Scaling error in utils.kerrnewman_utils.py #508 - Requires discussion
2. Mathematical error in utils.schwarzschild_utils.py #507 -time_velocity methods, across <Metric>_utils modules, have been moved to and repackaged into 1 function in coordinates.utils, renamed as v_t(). This function uses the supplied metric and 3-Velocity, and the expression for spacetime interval: $g_{ab} u^a u ^b = 0 or 1$ (null-like or time-like), to determine the timelike component of 4-Velocity, and hence it bypasses the method used in previous Schwarzschild, Kerr and KerrNewman classes.

Touched modules:

• einsteinpy.metric
• einsteinpy.utils
• einsteinpy.coordinates.utils
• geodesic
• examples
• plotting.geodesic
• test_metric
• test_utils
• test_coordinates/test_utils
• test_geodesic
• test_examples
• test_plotting/test_geodesic

Other files

• index.ipynb
• docs/source/jupyter.rst
• docs/source/user_guide
• docs/source/api/
• docs/source/examples/
• .codeclimate.yml
• CHANGELOG

Current changes:

1. New Metric class added and old metric API removed.
2. Moved calculate_trajectory() from metric to geodesic and time_velocity() (now v_t()) to coordinates.utils.
3. Merged most utility functions from utils into metric (only file untouched is scalar_factor.py)
4. Modified geodesic, examples and example Jupyter Notebooks to work with new API.
5. Added some new utilities to coordinates.utils.
6. Added tests for new API (metric, utils, geodesic, examples, plotting)
7. Moved calculate_trajectory() tests from test_metric to test_geodesic.

Pending changes:

• Alter code, after discussion on Scaling error in utils.kerrnewman_utils.py #508 - Factor removed.

• Modify examples to use new API

• Add functionality of calculate_trajectory to geodesic and create a warning in metric classes.

• Add tests (can refactor old tests).

• Fix CodeFactor and CodeClimate issues. - Linked to Refactor some functions in Schwarzschild and Kerr class #113.

• Add a changelog.

• Update User Guide.

• Update index.ipynb.

• Review list of issues fixed.

• Check if scaling in Frame Dragging Example breaks on New plotting code #367 is fixed now. Add a comment regarding the smooth plot.

• Issues, after review:

  • Benchmark and Validate the core Schwarzschild and Kerr Algorithms #122 - Check Kerr and Schwarzschild methods.
  • Write example notebooks for working with einsteinpy.metric.* #239 - Example notebooks for metric - After the review.
  • einsteinpy.bodies - Spin Factor, a is redundant #517 - Spin Factor is redundant in bodies - Discuss.

[pep8speaks]

Hello @JeS24! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file src/einsteinpy/coordinates/utils.py:

Line 242:9: W503 line break before binary operator
Line 243:9: W503 line break before binary operator
Line 244:9: W503 line break before binary operator

• In the file src/einsteinpy/metric/base_metric.py:

Line 297:17: W503 line break before binary operator
Line 303:17: W503 line break before binary operator
Line 320:17: W503 line break before binary operator
Line 324:17: W503 line break before binary operator

• In the file src/einsteinpy/metric/kerr.py:

Line 131:13: W503 line break before binary operator
Line 133:17: W503 line break before binary operator
Line 134:17: W503 line break before binary operator
Line 136:13: W503 line break before binary operator
Line 203:17: W503 line break before binary operator
Line 204:17: W503 line break before binary operator
Line 218:17: W503 line break before binary operator
Line 219:17: W503 line break before binary operator

• In the file src/einsteinpy/metric/kerrnewman.py:

Line 140:13: W503 line break before binary operator
Line 141:13: W503 line break before binary operator
Line 211:25: W503 line break before binary operator
Line 212:25: W503 line break before binary operator
Line 214:21: W503 line break before binary operator
Line 216:17: W503 line break before binary operator
Line 218:21: W503 line break before binary operator
Line 231:17: W503 line break before binary operator
Line 239:25: W503 line break before binary operator
Line 241:21: W503 line break before binary operator
Line 243:17: W503 line break before binary operator
Line 245:21: W503 line break before binary operator
Line 246:21: W503 line break before binary operator
Line 592:13: W503 line break before binary operator
Line 593:13: W503 line break before binary operator

• In the file src/einsteinpy/metric/schwarzschild.py:

Line 125:13: W503 line break before binary operator
Line 126:13: W503 line break before binary operator
Line 127:13: W503 line break before binary operator

• In the file tests/test_geodesics.py:

Line 131:35: W504 line break after binary operator
Line 132:35: W504 line break after binary operator
Line 133:35: W504 line break after binary operator
Line 368:35: W504 line break after binary operator
Line 369:35: W504 line break after binary operator
Line 370:35: W504 line break after binary operator
Line 371:35: W504 line break after binary operator

• In the file tests/test_metric/test_kerrnewman.py:

Line 163:81: W504 line break after binary operator

Comment last updated at 2020-06-24 19:24:05 UTC

[shreyasbapat]

All tests are failing. Do you expect them to fail?

[JeS24]

@shreyasbapat Not at all. The old files have not been modified, except for addition of deprecation warnings. According to the traceback, these are the tests, that have failed:

• Py38

1. test_geodesics/test_static.py::test_plot_in_3d
2. test_geodesics/test_interactive.py::test_plot_calls_draw_attractor_Manualscale

• Py37

  • Timed out:

  tests/test_symbolic/test_tensor.py::test_ValueError2  
  
  Too long with no output (exceeded 10m0s): context deadline exceeded
  

• Py36

1. test_plotting/test_geodesics/test_static.py::test_plot_in_3d
2. test_plotting/test_geodesics/test_interactive.py::test_plot_draws_fig
3. test_metric/test_kerrnewman.py::test_calculate_trajectory1
4. test_plotting/test_geodesics/test_static.py::test_plot_calls_draw_attractor_Manualscale
5. test_plotting/test_geodesics/test_static.py::test_staticgeodesicplotter_has_axes
6. test_plotting/test_geodesics/test_interactive.py::test_plot_calls_draw_attractor_Manualscale

None of the related files were modified in this PR, which makes this even weirder.

[shreyasbapat]

Can you force push once?

[JeS24]

@shreyasbapat It's telling me, "Everything up-to-date". So, I made a non-consequential change and pushed it.

[shreyasbapat]

You usually do

git commit --amend --no-edit
git push -f origin branch

[JeS24]

Okay, will keep this in reference. Do you want me to force push or let the tests run for now?

[shreyasbapat]

Okay, will keep this in reference. Do you want me to force push or let the tests run for now?

Oh, let them run now. Then I'll review

[shreyasbapat]

Have you made the changes discussed in the chats?

[JeS24]

The current failures are expected. I am modifying geodesics and examples, which should fix half of them.

[shreyasbapat]

Should I review?

[JeS24]

Tests for geodesic, examples and plotting.geodesic, plotting.examples are currently commented out. This is to check for any other test failure. Those tests will be back in the next few commits.

[shreyasbapat]

Any progress?

[shreyasbapat]

@JeS24 Do you have any fix for these codefactor issues?

[shreyasbapat]

Okay, whatever. Merging now.

[JeS24]

@JeS24 Do you have any fix for these codefactor issues?

I'm not sure about the cyclic imports issue, but the "unnecessary elif" ones are simple to fix.