stan-dev / stan-dev/rstan

Use parallel interface when computing summary

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Dominant language
R
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Description

Computing ess and Rhat in summary can be quite slow. It seems that this can be paralleleized quite easily by switiching the sapply's to parSapply. I started to make the changes, but wanted to check in here to see if that makes sense. In particular, I don't want to break things for windows users by relying on unsupported functions. However, it seems that R already uses mclapply, which makes me think parallel processing in Rstan is not available on windows anyway.

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Research direction

Start at the summary implementation and locate the sapply calls used to compute ESS and Rhat. Check whether replacing them with parSapply preserves supported behavior, especially on Windows; done means summary computation is parallelized without breaking platform compatibility.

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Assessment

Tech stack
r
Domain
performance
Issue type
Refactor
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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