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alashworth / test-issue-import

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expose HyperGeometric 2F1 #96

Open alashworth opened 5 years ago

alashworth commented 5 years ago

Issue by wds15 Tuesday May 10, 2016 at 19:22 GMT Originally opened as https://github.com/stan-dev/stan/issues/1889

Summary:

Expose the stan math function HyperGeometric 2F1

Description:

The 2F1 function is the analytic solution to some ODE systems which are relevant to PK/PD problems and would be very useful to have in Stan.

Reproducible Steps:

None.

Current Output:

NA

Expected Output:

NA

Additional Information:

NA

Current Version:

v2.9.0

alashworth commented 5 years ago

Comment by syclik Friday May 27, 2016 at 17:11 GMT

@wds15, I don't think we have an implementation of hypergeometric 2F1 in the math library. We definitely have a function for the gradient, though:

Steps someone will need to take:

  1. Create a hypergeometric 2F1 function in the Stan math library
  2. Expose the function in the Stan language.
alashworth commented 5 years ago

Comment by wds15 Friday Jun 03, 2016 at 15:54 GMT

@syclik hmmm.... I thought @betanalpha has this function ready. I am not sure if I can provide an implementation as I have no experience with this 2F1 buisness, I was hoping @betanalpha has code ready and we only need to expose it.