Fix a missing factor of 2 in the Fisher Matrix proposals
Reviewing the bilby_mcmc
Fisher Matrix Proposals, I realised we are missing a factor of 2 in using the inverse Fisher matrix as a covariance matrix. To test out the change, I reran the GW150914 review analysis with and without the change:
Analysis | ACT | Efficiency |
---|---|---|
Original analysis without factor of 2 | 210+/-90 | 0.065% |
Analysis with factor 2 fixed) | 180 +/- 80 | 0.072% |
Hence, one sees a modest improvement in the efficiency. Meanwhile, all comparison plots still pass the JS test.