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emcee-odi

 emcee-odi

My talk at the "Open Digital Infrastructure in Astrophysics" meeting.

Dan Foreman-Mackey

June 04, 2019
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  1. A modular ecosystem for probabilistic data analysis including emcee Dan

    Foreman-Mackey CCA@Flatiron // dfm.io // @exoplaneteer // github.com/dfm
  2. – 8 – Algorithm 3 The parallel stretch move update

    step 1: for i ∈ {0, 1} do 2: for k = 1, . . . , K/2 do 3: // This loop can now be done in parallel for all k 4: Draw a walker Xj at random from the complementary ensemble S(∼i)(t) 5: Xk ← S(i) k 6: z ← Z ∼ g(z), Equation (10) 7: Y ← Xj + z [Xk (t) − Xj ] 8: q ← zn−1 p(Y )/p(Xk (t)) 9: r ← R ∼ [0, 1] 10: if r ≤ q, Equation (9) then 11: Xk (t + 1 2 ) ← Y 12: else 13: Xk (t + 1 2 ) ← Xk (t) 14: end if 15: end for 16: t ← t + 1 2 17: end for acceptance fraction af . This is the fraction of proposed steps that are accepted. There appears to be no agreement on the optimal acceptance rate but it is clear that both extrema are unacceptable. If af ∼ 0, then nearly all proposed steps are rejected, so the chain DFM+ (2013)
  3. 1 Releasing your code can be good for your career

    . * Prior results do not guarantee a similar outcome.
  4. AstroPy is a much more successful open source project by

    all metrics. Except citation count.
  5. data from: ui.adsabs.harvard.edu 2013 2014 2015 2016 2017 2018 2019

    year 0 1000 2000 3000 cumulative citations astropy
  6. 2013 2014 2015 2016 2017 2018 2019 year 0 1000

    2000 3000 cumulative citations astropy emcee data from: ui.adsabs.harvard.edu
  7. I want to learn how to continue to maintain this

    software and build a sustainable community .