nmfs-ost / ss3-source-code

The source code for Stock Synthesis (SS3).
https://nmfs-ost.github.io/ss3-website/
Creative Commons Zero v1.0 Universal
36 stars 16 forks source link

[Feature]: Cohort growth deviation added to Linf (or L2) #599

Open peterkuriyama-NOAA opened 3 months ago

peterkuriyama-NOAA commented 3 months ago

Describe the solution you would like.

Cohort growth deviation multiplier is only applied to von Bert k. I was hoping it could be applied to Linf or L2 to have a more consistent growth pattern. I think as a start it may be ok to have the same growth deviation applied to both parameters.

Describe alternatives you have considered

I have tried to estimate cohort growth deviations with a year-specific deviation on Linf. That sort of growth pattern has been difficult to justify given it is neither a cohort nor year-specific growth pattern.

Statistical validity, if applicable

No response

Describe if this is needed for a management application

No response

Additional context

No response

Rick-Methot-NOAA commented 3 months ago

There already is code to do Lmin:

              Cohort_Lmin(gp, y + a, a) = Lmin(gp);
            } //  sets for future years so cohort remembers its size at birth; with Lmin(gp) being size at birth this year

It should be straightforward to create and use: Cohort_Lmax()