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Need help understanding r4ss catch plot (observed vs. predicted)

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Thom D. Teears, modified 3 Years ago.

Need help understanding r4ss catch plot (observed vs. predicted)

Youngling Posts: 23 Join Date: 8/13/18 Recent Posts

Hello all,

     I was wondering if anyone might be able to help me understand the catch plot generated by r4ss that I have attached below. The total catch likelihood is very low (1.48E-05) suggesting a good fit to the landings however, the plot shows that the fit is not what I expected.

 

Any help would be greatly appreciated.

 

Thanks,

Thom

Attachments:

Attachment

Richard Methot, modified 3 Years ago.

RE: Need help understanding r4ss catch plot (observed vs. predicted)

Youngling Posts: 219 Join Date: 11/24/14 Recent Posts

Hi Thom,

I think I would need to get more info to be sure.  What F method are you using?  What is the catch se?  Is F hitting the max possible F level set in the control file?  It might help to look at the source info for the plots.  The sections of the  report.sso labelled EXPLOITATION and CATCH have good details that may help.

Rick

TT
Thom D. Teears, modified 3 Years ago.

RE: Need help understanding r4ss catch plot (observed vs. predicted)

Youngling Posts: 23 Join Date: 8/13/18 Recent Posts

Thanks for your reply Rick. I am using the hybrid F method and the max F is set to 2.95. The highest F value in the exploitation section of the report file is 1.64. In the catch section of the report file it indicates observed and expected values that are nearly identical for most years.

I was wondering if it is because my catch for fleet 1 is in numbers whereas the graph is in metric tons. Could that be the problem?

 

Thanks,

Thom

 

IT
Ian Taylor, modified 3 Years ago.

RE: Need help understanding r4ss catch plot (observed vs. predicted)

Youngling Posts: 117 Join Date: 12/8/14 Recent Posts
Hi Thom,
The numbers/biomass issue is surely the source of the difference in this figure. See discussion at https://github.com/r4ss/r4ss/issues/312 about this.
An easy, short-term fix would be to expand the figure caption for any model with any catch input in numbers to note that this figure is comparing apples to oranges.
-Ian

On Mon, Mar 29, 2021 at 3:26 PM Thom D. Teears <VLab.Notifications@noaa.gov> wrote:

Thanks for your reply Rick. I am using the hybrid F method and the max F is set to 2.95. The highest F value in the exploitation section of the report file is 1.64. In the catch section of the report file it indicates observed and expected values that are nearly identical for most years.

I was wondering if it is because my catch for fleet 1 is in numbers whereas the graph is in metric tons. Could that be the problem?

 

Thanks,

Thom

 


--
Thom D. Teears Stock Synthesis Virtual Lab Forum https://vlab.noaa.gov/web/stock-synthesis/public-forums/-/message_boards/view_message/14278696 VLab.Notifications@noaa.gov
TT
Thom D. Teears, modified 3 Years ago.

RE: Need help understanding r4ss catch plot (observed vs. predicted)

Youngling Posts: 23 Join Date: 8/13/18 Recent Posts

Thank you for the clarification. I really appreciate it. That is very helpful.