Update code to use BMSTransformation class and add function to map ABD object to the frame of another #85
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…ption to map abd objects to the frame of another abd object via map_to_abd_frame.py
|
Oh I've also noticed that the tolerances in the transformation code regarding supertranslations are a bit stringent. @moble how did you come up with these? Can we relax them? |
moble
reviewed
Mar 15, 2023
|
Looks like there are some sxs/scri compatibility issues. Working on a fix and will push sometime next week. |
| """ | ||
| ell_max = 1 # Compute only the parts we need, ell<=1 | ||
| supertranslation_potential_data = scri.asymptotic_bondi_data.map_to_superrest_frame.𝔇inverse( | ||
| np.array(self.sigma.ethbar_GHP.ethbar_GHP + self.sigma.bar.eth_GHP.eth_GHP), self.ell_max |
There was a problem hiding this comment.
Is it faster to just compute self.sigma.ethbar_GHP.ethbar_GHP and take twice the real part?
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR updates the
map_to_superrest_frame.pycode to use the classscri.bms_transformations.BMSTransformationto keep track of the BMS transformations that we're applying. By doing so, this enables us to only ever transform the original ABD object (since we can compose transformations), which, in theory, should help reduce numerical noise.Apart from updating the
map_to_superrest_frame.pycode, this also adds a new file,map_to_abd_frame.py, which includes the functionmap_to_abd_frame. This function maps one ABD object to the frame of another.This is achieved by doing the following:
target_ABDto the superrest frame; call itT1selfto the superrest frame; call itT2selftotarget_ABDviaT1.inverse() * T_time_phase * T2To ensure this function works as expected, the test file
test_abd_frame.pyhas also been added.One thing I'm unsure of is how to define the error between the two ABD objects. If the user chooses to do an optimization over the time/phase freedom, then the error is simply the relative error between the strain waveforms. If not, then the error is defined to be the average of the relative error of the Weyl scalars and strain. I don't think this should matter too much, but if people have ideas that are better than what I've implemented, I'd be happy to change the code accordingly.
@moble @duetosymmetry might find this of interest.