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Dan Fu, modified 4 Years ago.

ss3 projection

Youngling Posts: 46 Join Date: 12/14/16 Recent Posts

Hi, I have come across an issue when doing standard ss3 projections  where the stock 'crashes' in some future years with certain catch senarios ( biomass/F values is too big or too small). I I don't think this is because the the catch has been set too high, as the projection with a much higher catch senario works fine. This appears to be an numeric issue as  simply rounding the catch numbers to fewer decimal places can fix the problem in some instances.  I wonder if someone has come across similar issues before? Thanks. Dan  

Richard Methot, modified 4 Years ago.

RE: ss3 projection

Youngling Posts: 219 Join Date: 11/24/14 Recent Posts
Hi Dan,
That is indeed a mysterious occurrence.  I know that long projections that have moderately high catch, high sigmaR, and use forecast loop 3 could crash in a MCMC, but your situation seems unique.  Can you send your input files to me at richard.methot@noaa.gov so I can diagnose.

On Fri, Sep 20, 2019 at 5:41 AM Dan Fu <VLab.Notifications@noaa.gov> wrote:

Hi, I have come across an issue when doing standard ss3 projections  where the stock 'crashes' in some future years with certain catch senarios ( biomass/F values is too big or too small). I I don't think this is because the the catch has been set too high, as the projection with a much higher catch senario works fine. This appears to be an numeric issue as  simply rounding the catch numbers to fewer decimal places can fix the problem in some instances.  I wonder if someone has come across similar issues before? Thanks. Dan  


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Dan Fu Stock Synthesis Virtual Lab Forum https://vlab.noaa.gov/group/stock-synthesis/discussions-forums-/-/message_boards/view_message/7647388 VLab.Notifications@noaa.gov


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Richard D. Methot Jr. Ph.D.
NOAA Fisheries Senior Scientist for Stock Assessments
Mobile: 301-787-0241