Improving MCMC Convergence for Joint Astrometry and Radial Velocity Orbit-fits Through Reparameterization
Bibliographic record
Abstract
Abstract The exoplanet orbit-fitting software package orbitize ! was initially designed to fit the orbits of directly imaged planets with relative astrometric measurements using a Markov Chain Monte Carlo (MCMC) algorithm. Since the publication of orbitize! v1.0, the ability to jointly fit radial velocities and astrometry has been incorporated. We first implemented a Basis class into orbitize! that enables users to add and fit in various orbit parameterizations. We then introduced a radial velocity-focused parameterization of the Keplerian orbital elements for the joint radial velocity and astrometry fits. We compared MCMC convergence speeds of the new radial velocity-focused basis to the original orbitize! standard basis for the system HD 190771, which has full orbital coverage in radial velocity data. We found a 16% faster convergence in time with the radial velocity-focused basis. We encourage users to consider using this basis when doing joint radial velocity and astrometry fits.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".